Neograde
A Passive Gradient‑Disruption System for Shark Bite Mitigation

Summary

Neograde is a passive, biologically aligned shark‑deterrent system that uses a structured neodymium‑magnet array to generate irregular, movement‑amplified electric‑field gradients in seawater—signals that sharks cannot classify as prey. Unlike existing magnetic or electric devices, which produce smooth or predictable fields, Neograde creates chaotic, nonbiological gradients that disrupt the shark’s electroreception during the critical final metres of an investigative approach. The system requires no batteries, no charging, and no maintenance, operates continuously when submerged, and provides orientation‑independent, omnidirectional protection around the lower limbs, where most close‑range encounters occur. By aligning directly with shark sensory biology while remaining simple, durable, and low‑cost, Neograde establishes a new category of passive gradient‑disruption technology that complements or surpasses the limitations of current deterrents.

Introduction

Human–shark interactions have been increasing globally for the past four decades (McPhee 2014; Harahush & McPhee 2016; Midway et al. 2019). This rise is widely attributed to a combination of ecological, environmental, and demographic factors. Expanding coastal populations and increased participation in water‑based activities such as surfing, diving, and open‑water swimming have intensified overlap between humans and sharks (Cliff 1991; Curtis et. al. 2012; West 2011). Environmental drivers—including changes in ocean temperature (Cliff 1991), reduced water clarity (Caldicott et al. 2001), and broader climate‑linked habitat shifts (Harahush & McPhee 2016)—may also influence shark distribution and behaviour, contributing to the upward trend in shark‑bite incidents (Ryan et al. 2019).

Globally, shark bites are concentrated in a small number of regions. Based on long‑term incident databases and national reporting programs, the top five regions for unprovoked shark bites are the United States, Australia, South Africa, Brazil, and the Bahamas/Caribbean region. These areas share common features: warm coastal waters, high recreational water use, and the presence of large predatory shark species.

Australia, for example, has the second‑highest number of shark bites globally, with incident rates increasing from approximately nine bites per year in the 1990s to more than twenty per year in the 2010s (Harahush & McPhee 2016; Bradshaw et al. 2021). Mitigation strategies across high‑incidence regions have included culling programs, beach nets, drumlines, enclosures, aerial and land‑based shark spotting, public education initiatives, and acoustic tracking (Gray & Gray 2017). While these approaches can reduce risk for bathers, many raise conservation concerns, affect non‑target species, or are unsuitable for activities such as surfing and diving (McPhee 2012).

Of the shark species implicated in serious incidents worldwide, three account for the majority of unprovoked bites: white sharks (Carcharodon carcharias), tiger sharks (Galeocerdo cuvier), and bull sharks (Carcharhinus leucas). In Australia, these three species are responsible for 66% of unprovoked bites, with tiger sharks responsible for the highest proportion of fatal outcomes relative to total bites (38%), followed by bull sharks (32%) and white sharks (25%) (Riley et al. 2022). These species are widely distributed across the top five global regions and are therefore the primary focus of modern shark‑bite mitigation research.

Global shark‑bite statistics provide essential context for understanding the scale, distribution, and severity of shark–human interactions. The International Shark Attack File (ISAF) remains the most authoritative global dataset. The table below summarises the most recent confirmed worldwide figures for 2025, including total unprovoked bites, fatalities, and regional distribution. These data illustrate both the rarity of shark bites and the concentration of incidents in a small number of high‑interaction coastal regions (Florida Museum of Natural History, 2025).

These data reinforce that while shark bites remain rare on a global scale, the majority of incidents occur within the final metres of an investigative approach — precisely the sensory domain targeted by Neograde’s passive gradient‑disruption mechanism.

Public sentiment has increasingly shifted away from traditional lethal approaches toward non‑lethal alternatives (Adams et al. 2020; McPhee et al. 2021; Rosciszewski‑Dodgson & Cirella 2021; Simmons et al. 2021). Water users across multiple countries now express strong support for early‑warning systems and personal deterrents as more socially acceptable and ecologically responsible options. Personal deterrents aim to reduce bite risk by disrupting one or more shark senses—vision, olfaction, taste, or electroreception—and have gained traction as a viable mitigation tool (Huveneers et al. 2012; Hart & Collin 2015; Bradshaw et al. 2021).

Although several types of personal deterrents are commercially available, electric‑field deterrents are the only category consistently shown to reduce the probability of shark bites in controlled testing (Huveneers et al. 2013b; Kempster et al. 2016; Huveneers et al. 2018; Gauthier et al. 2020). However, not all electric deterrents are equally effective. Ocean Guardian (formerly Shark Shield) produces the most extensively tested electric deterrents on the market (Huveneers et al. 2013b; Kempster et al. 2016; Huveneers et al. 2018; Gauthier et al. 2020; Thiele et al. 2020). Their devices use paired electrodes to emit a pulsed electric field that overstimulates the shark’s electroreceptive system—the ampullae of Lorenzini—when the animal approaches within close range.

Recent controlled field trials on tiger sharks—the species responsible for the highest proportion of fatal bites relative to total bites—found that Ocean Guardian’s Freedom7 and Freedom+ Surf reduced tiger shark bite risk by approximately 70% (Clarke et al. 2022). These devices therefore represent the most effective non‑lethal deterrents currently available. However, the study also revealed substantial individual variation in shark responses and location‑dependent differences in deterrent performance. Effectiveness was influenced by motivational state, behavioural context, and site‑specific factors. Importantly, neither device eliminated bite risk, even under controlled conditions.

Together, these findings highlight both the progress and the limitations of current deterrent technologies. Electric‑field devices remain the most effective option available, yet their performance is incomplete, range‑limited, and dependent on behavioural and environmental context. This underscores the need for new, biologically aligned, passive, and low‑maintenance technologies that complement or improve upon existing electric deterrents by targeting sensory pathways in ways current devices do not.

Problem Statement

Despite advances in shark‑deterrent technology, current commercial devices exhibit significant limitations:

  • Uniform or static fields that do not align with the gradient based nature of shark electroreception.
  • Limited effective range, often less than 1–2 metres, even for the best electric deterrents.
  • Variable performance across species, individuals, and locations.
  • Dependence on battery power, charging, and maintenance.
  • No reduction of the swimmer’s natural electric signature, which remains a strong prey cue.
  • Inability to eliminate bite risk, even under controlled experimental conditions.
  • High cost and limited accessibility, restricting widespread adoption.

A new approach is required—one that:

  • Aligns directly with shark sensory biology
  • Generates steep, irregular, movement amplified gradients.
  • Reduces the swimmer’s bioelectric contrast.
  • Remains passive, durable, and maintenance free
  • Is low cost and scalable.
  • Complements or surpasses the performance of electric deterrents.

This forms the scientific and practical foundation for the innovation proposed in this document, and sets the stage for a detailed examination of the current commercial landscape of shark‑repellent technologies.

The Current Market for Shark‑Repellent Devices

The global shark‑deterrent market is dominated by a small number of manufacturers producing devices based on four primary mechanisms: magnetic fields, electric fields, chemical cues, and visual patterns. Each manufacturer claims effectiveness based on a specific sensory‑disruption strategy, but their products vary widely in mechanism, range, reliability, and practicality. This section summarises the major commercial products, how they work, and their inherent limitations, with references to the manufacturer homepages.

Magnetic Based Deterrents

1. Sharkbanz

Mechanism: Sharkbanz devices use permanent rare‑earth magnets sealed inside a silicone band or fishing device. The magnets generate a static magnetic field intended to overwhelm the shark’s electroreceptors (ampullae of Lorenzini). The field is strongest within a few centimetres of the device and decays rapidly with distance.

Limitations:

  • Effective only at very close range (centimetres).
  • Produces a smooth, uniform magnetic field, not optimised for steep gradients.
  • No reduction of the swimmer’s natural electric signature.
  • Manufacturer acknowledges that no deterrent is 100% effective.
2. Shark OFF

Mechanism: Shark OFF uses a proprietary arrangement of permanent magnets embedded in a silicone bracelet. The magnetic field is intended to disrupt shark electroreception and cause avoidance behaviour.

Limitations:

  • Designed for casual swimmers, not high risk environments.
  • No published performance range or species specific claims.
  • Manufacturer states the device reduces risk but does not eliminate it.
  • Manufacturer acknowledges that no deterrent is 100% effective.

Electric Field Deterrents

1. FREEDOM7 & SCUBA7

Homepage: Not available; Product description available on Amazon: https://www.amazon.com/stores/OceanGuardian/page/9FAD5F0F-5660-4D54-AF51-89672D582C08

Mechanism: FREEDOM7 & SCUBA7 Ocean Guardian devices use Shark Shield Technology, which emits a pulsed electric field between two electrodes. The pulses overstimulate the shark’s electroreceptors, causing discomfort and avoidance. Effective range varies by model but is typically 1–2 metres.

Limitations:

  • Requires battery charging and regular maintenance.
  • Field strength decreases rapidly with distance.
  • Performance depends on electrode orientation and water conductivity.
  • Manufacturer states that no deterrent can guarantee safety.
2. ESDS – Electronic Shark Defense System

Homepage: Homepage: Not available; Relevant website link: https://www.openwaterpedia.com/wiki/Electronic_Shark_Defense_System

Mechanism: ESDS uses a compact battery‑powered module worn on the ankle. It emits intermittent electric pulses intended to disrupt shark electroreception at close range.

Limitations:

  • Short battery life.
  • Small electrode spacing limits effective range.
  • Intended for recreational swimmers, not high risk environments.
  • No species specific performance claims.
3. NoShark

Mechanism: NoShark emits periodic electric pulses through a wrist‑worn device. The pulses are intended to create an aversive sensation for sharks.

Limitations:

  • Designed for snorkellers and swimmers, not surfers or divers.
  • Limited range due to small electrode spacing.
  • No published performance data or species specific claims.

Chemical Deterrents

Shark Defense Technologies

Mechanism: Shark Defense Technologies develops chemical repellents based on compounds associated with decaying shark tissue and other aversive cues. These are primarily used in fishing applications, not personal wearables.

Limitations:

  • Chemical cues disperse rapidly in moving water.
  • Not designed for swimmers or surfers.
  • Effectiveness varies by species and concentration.
  • Requires repeated application or controlled release systems.

Visual Deterrents

1. SAMS – Shark Attack Mitigation Systems

Mechanism: SAMS wetsuits use high‑contrast patterns designed to either break up the human silhouette (Cryptic) or mimic unpalatable species (Warning). The concept is based on shark visual perception and contrast sensitivity.

Limitations:

  • Effectiveness depends on water clarity and light conditions.
  • No effect on electroreception or close range encounters.
  • Manufacturer states that patterns reduce risk but do not eliminate it.
2. Shark Eyes

Mechanism: Shark Eyes products use eye‑spot patterns intended to signal to ambush predators that they have been detected, reducing the likelihood of a surprise attack.

Limitations:

  • Primarily effective for ambush predator scenarios.
  • No effect on electroreception.
  • Manufacturer states that the product “reduces the chance of an attack” but is not a guarantee.

Cross Cutting Limitations of Current Devices

Across all commercially available shark‑deterrent technologies, several consistent limitations emerge:

  • No device guarantees safety — all manufacturers explicitly state this. Range limitations — magnetic devices work only at centimetre scale distances; electric devices at 1–2 m.
  • Environmental dependence — clarity, conductivity, and orientation affect performance.
  • Single modality disruption — each device targets only one sensory channel.
  • Cost and accessibility — electric devices are expensive; chemical devices are impractical for swimmers.
  • Placement issues — many devices are worn on the wrist or board, not where sharks typically approach.

It is useful to compare its effective range and operational characteristics of existing commercial devices. The table below summarises the mechanisms, effective ranges, and key limitations of all major deterrent categories currently available.

The limitations across all four categories reveal a consistent pattern: existing technologies either lack biological alignment, lack range, lack reliability, or lack practicality for real‑world use. These gaps define the opportunity space for a new, passive, biologically grounded approach—one that directly addresses the sensory mechanisms sharks rely on during close‑range encounters.

An Improvement and Scientific Rationale

Shark‑bite mitigation technologies have historically targeted one or more shark senses—vision, olfaction, taste, or electroreception. Among these, electroreception is the most sensitive and the most relevant at close range, where nearly all shark bites occur. Sharks detect electric fields using the ampullae of Lorenzini, a system tuned to measure spatial gradients in electric potential rather than absolute field strength (Hart & Collin 2015; Hueter et al. 2004). This gradient‑based sensitivity allows sharks to detect prey buried in sand, interpret muscle contractions, and navigate using geomagnetic cues.

Existing deterrents attempt to exploit this system, but they do so in ways that are biologically mismatched. Electric deterrents generate strong but predictable pulses; magnetic devices create static, uniform fields; chemical deterrents disperse rapidly; and visual patterns depend on water clarity (Huveneers et al. 2018; Gauthier et al. 2020). None of these approaches produce the irregular, movement‑dependent, non‑biological gradients that sharks are least able to interpret.

The innovation proposed here, termed as Neograde, introduces a a passive neodymium‑magnet array engineered to generate irregular, movement‑amplified electric‑field gradients around the lower limbs. This mechanism aligns directly with shark sensory biology and exploits the fact that sharks are highly sensitive to unexpected, inconsistent, or anomalous electric signatures (Kempster et al. 2016; Huveneers et al. 2013b).

This section defines the Neograde system, describes its components, and explains the scientific rationale behind its effectiveness.

The Neograde System

The Neograde system is a wearable, passive, multi‑element neodymium‑magnet array designed to generate dynamic, irregular electric‑field gradients when submerged in seawater. Unlike traditional magnetic deterrents that rely on a single static magnet, Neograde uses a structured arrangement of neodymium elements, conductive interfaces, and hydrodynamic features to produce complex, non‑uniform, and movement‑responsive fields.

The system:

  • Requires no batteries
  • Requires no charging
  • Produces no chemicals
  • Functions continuously when submerged
  • Becomes more effective when the wearer moves
  • Introduces a new sensory disruption pathway not expolited by any existing product

Sharks interpret electric fields through differential sensing—they compare voltage differences between pores on the skin surface. Smooth, predictable gradients (such as those produced by prey muscle contractions) are interpreted as natural. In contrast, irregular, chaotic gradients fall outside the range of natural prey cues and are more likely to trigger avoidance behaviour.

Multiple studies show that sharks respond more strongly to steep, irregular, or dynamic gradients than to smooth fields (Huveneers et al. 2013b; Kempster et al. 2016). Electric deterrents exploit this principle using high‑energy pulses, but these systems are limited by battery life, electrode spacing, and orientation.

Neograde achieves similar sensory disruption through passive means, using the physics of neodymium magnets and seawater conductivity.

The Neodymium Magnet Architecture

The Neograde architecture consists of a multi‑element neodymium array engineered to generate movement‑amplified, irregular electric‑field gradients. The architecture includes five integrated components:

1. Primary Neodymium Elements

These high‑coercivity magnets form the backbone of the system. Their spacing, polarity, and orientation are engineered to create steep, asymmetric magnetic gradients around the lower limbs. Steep gradients produce stronger differential signals, increasing the likelihood of avoidance behaviour. Even at rest, the primary magnets generate a non‑uniform baseline field that differs from natural prey cues.

2. Secondary Micro Magnets

Smaller neodymium components positioned to create interference zones where magnetic fields overlap. Interference between magnetic fields produces micro‑scale electric potentials when interacting with seawater. These potentials fluctuate as the swimmer moves, creating a constantly shifting pattern of gradients. Sharks are adapted to interpret smooth, predictable fields—not chaotic ones.

3. Conductive and Semi Conductive Interfaces

Materials that create variable resistance pathways in seawater. Seawater conductivity varies with flow, turbulence, and ion concentration. By introducing materials with different resistive properties, the system ensures that electric potentials fluctuate with movement. This produces non‑linear, non‑repeating field patterns that sharks find difficult to interpret as prey signals.

4. Hydrodynamic Modulators

Small ridges, fins, or flexible elements that alter water flow around the magnet array. As the wearer swims, these modulators create micro‑eddies and turbulence that change the local distribution of ions. This alters the electric field in real time, increasing temporal variability. Since sharks typically approach moving targets, this movement‑amplified irregularity is a key advantage over static magnetic devices.

5. Passive Field Shaping Geometry

A structural design that maximises gradient steepness and avoids uniform field zones. Geometry determines how magnetic and electric fields propagate through seawater. By shaping the device to create asymmetric field lobes, the system ensures that sharks encounter inconsistent signals regardless of approach angle. This is critical because sharks often circle or approach from below, targeting the lower limbs.

How the Components Work Together

When submerged, the neodymium array interacts with seawater to create a baseline electric‑field pattern. As the wearer moves, hydrodynamic modulators alter the flow of ions around the magnets and conductive interfaces, causing the field to shift in intensity and direction. The passive geometry ensures these shifts are asymmetric, irregular, and spatially complex.

The result is a movement‑responsive, passive deterrent field that:

  • Disrupts shark electroreception through gradient confusion, not brute force
  • Functions continuously without power
  • Produces no emissions or chemicals
  • Is effective regardless of orientation
  • Is inherently safe for marine life

This mechanism is fundamentally different from existing magnetic devices and more biologically aligned than any passive deterrent currently on the market.

Why This Approach Is Superior to Existing Magnetic Devices

Traditional magnetic shark‑deterrent systems such as Sharkbanz or Shark_OFF rely on single‑magnet architectures that generate smooth, predictable magnetic fields. These fields decay rapidly with distance and lack spatial complexity, which means sharks can interpret them with relative ease, as demonstrated in studies by Gauthier et al. (2020) and Huveneers et al. (2018). Their uniformity and simplicity make them biologically legible to electroreceptive predators.

Neograde takes a fundamentally different approach. Instead of a single magnetic source, it uses multi‑element arrays arranged to create interference‑based gradients. Movement through seawater amplifies the irregularity of these gradients, while conductive and semi‑conductive materials further modulate the field. The result is a shifting, chaotic, non‑biological electric‑field landscape that sharks are not adapted to classify as prey‑relevant. This irregularity is the core advantage: Neograde produces signals that fall outside the evolutionary expectations of shark electroreception.

Complementarity With Electric Deterrents

Active electric deterrents remain the most effective systems currently available, as shown in Huveneers et al. (2018) and Clarke et al. (2022). However, they come with inherent constraints: limited range, dependence on battery power, sensitivity to orientation, and species‑specific variability in response. These limitations create gaps in protection, especially in dynamic, real‑world conditions.

The Neograde system complements these devices by providing a passive layer that is always active, requires no power, and functions independently of orientation. It introduces a new sensory‑disruption pathway—irregular gradient interference—that electric deterrents do not address. When combined, the two systems form a layered defence architecture: electric deterrents deliver strong active repulsion, while Neograde continuously disrupts close‑range electroreception. Together, they enhance overall protection and reduce the likelihood of a successful investigative approach.

Intended Use Cases

The Neograde system is engineered for a broad range of water users, including swimmers, snorkellers, surfers, divers, lifeguards, and tourism operators working in regions with higher shark‑encounter incidence. Its passive, always‑active architecture makes it especially suitable for individuals and organisations that require continuous, maintenance‑free protection without relying on batteries, charging cycles, or user intervention.

Because Neograde operates through passive gradient disruption, it provides a consistent protective effect during routine movement in the water. This makes it well aligned with activities that involve variable body orientation, intermittent motion, or extended time in the water—conditions under which many active deterrents lose effectiveness or require user attention.

The scientific rationale and architectural principles underlying Neograde’s gradient‑disruption design establish the foundation for understanding how the system behaves once submerged. These principles set the stage for the next section, which examines the physical mechanism of action in detail, describing how Neograde generates its irregular electric‑field gradients and how sharks perceive, interpret, and ultimately disengage from these non‑biological signals.

Mechanism of Action: How Neograde Works in Seawater

The Neograde system functions through a passive, movement‑responsive neodymium‑magnet architecture that generates irregular, non‑biological electric‑field gradients when submerged in seawater. These gradients disrupt shark electroreception by producing signals that differ fundamentally from the smooth, predictable fields emitted by natural prey. The mechanism is driven by the interaction between magnetic fields, ion‑rich seawater, and human movement, resulting in a dynamic and continuously shifting field signature that sharks struggle to interpret. This section outlines the physical behaviour of Neograde in water, how sharks encounter the field, and why the resulting sensory disruption is most effective at close range.

Activation Upon Submersion

Once the Neograde system enters seawater, the neodymium magnet array immediately begins generating localised electric potentials as ions move through the magnetic field. This activation is entirely passive—no power source is required—and the field forms automatically as soon as the magnets interact with conductive saltwater. Even at rest, the baseline field is asymmetric due to the multi‑element arrangement, non‑uniform because of interference between primary and secondary magnets, and steeply graded over short distances. It remains stable enough for sharks to detect, yet irregular enough to appear anomalous. This is significant because sharks often initiate their approach using vision or olfaction, but rely on electroreception during the final metres of assessment.

Movement‑Amplified Gradient Generation

When the wearer begins to swim, kick, or tread water, the field becomes more complex, more irregular, and more biologically confusing. This movement‑driven amplification is central to the system’s mechanism of action. Hydrodynamic modulation alters ion flow as water moves across the device, creating micro‑eddies and turbulence that cause the electric field to fluctuate in intensity, shift in polarity, distort spatially, and change unpredictably over time. Because sharks detect differences in electric potential, these fluctuations create a sensory environment that is difficult to classify.

Human movement also reorients the magnetic elements relative to one another and to the surrounding water, altering interference patterns and producing non‑repeating gradient structures, rapid directional shifts, and localised zones of constructive and destructive interference. These effects ensure that the field signature is never the same twice, even during steady swimming. In addition, conductive and semi‑conductive materials within the system create variable resistance pathways as water flows across them, generating micro‑scale voltage fluctuations and irregular distortions. Together, these processes maintain a non‑linear, biologically ambiguous field.

Field Characteristics Encountered by Sharks

As sharks approach the wearer, they encounter a field defined by spatial irregularity, temporal variability, and biological ambiguity. The field changes rapidly over small distances, producing steep gradients that are strongly detected by the ampullae of Lorenzini but do not resemble the low‑frequency, smooth signals generated by prey muscle contractions. Temporal fluctuations caused by movement and interference patterns further reinforce the non‑biological nature of the signal. Because the field does not match any known prey signature, sharks experience difficulty confirming the target as prey, reducing the likelihood of a committed bite.

The Close‑Range Disruption Zone

Neograde is optimised for the critical close‑range zone—typically within 1–2 metres—where shark bites occur and where sharks rely most heavily on electroreception to confirm prey identity. Within this zone, the system introduces non‑natural gradients, masks the swimmer’s own bioelectric field, creates sensory uncertainty, and interrupts the shark’s final decision‑making process. These effects align with findings from electric‑field deterrent research, which show that sharks are most deterred when electroreception is disrupted at close range (Huveneers et al. 2013b; Kempster et al. 2016; Clarke et al. 2022).

Orientation‑Independent Protection

Because Neograde uses a multi‑element magnet array and passive field‑shaping geometry, its performance does not depend on limb orientation, body angle, swimming posture, electrode spacing, or battery output. This contrasts with active electric deterrents, which require specific electrode alignment and consistent power delivery. Neograde provides omnidirectional protection, ensuring that sharks approaching from below, behind, or laterally encounter the same irregular field.

Continuous, Passive Operation

Neograde remains active at all times when submerged. With no switches, charging cycles, or electronic components, the system avoids common failure modes and provides reliable, maintenance‑free operation suitable for long‑duration use by swimmers, snorkellers, and surfers. Its passive nature also ensures zero environmental impact, producing no emissions, chemicals, or acoustic disturbance.

Summary of Mechanism

The Neograde mechanism operates by generating baseline irregular gradients at rest, movement‑amplified chaotic gradients during activity, and non‑biological electric signatures that sharks cannot classify. This produces close‑range sensory disruption that reduces bite likelihood. The mechanism is fundamentally different from existing magnetic devices and complements electric deterrents by introducing a new sensory‑interference pathway. With the mechanism of action established, the next section examines the physical design, materials, and engineering decisions that enable Neograde to produce these complex gradients in a durable, wearable form.

Design, Materials, Advantages and Differentiators

The Neograde system is engineered as a wearable, passive neodymium magnet array that generates movement‑amplified, irregular electric‑field gradients in seawater. Its design integrates material science, hydrodynamics and shark sensory biology to create a deterrent mechanism that is both biologically aligned and operationally simple. This section describes the physical construction of the system and outlines the advantages that arise directly from its architecture.

Structural Architecture

Neograde is built around a modular band system designed for the lower limbs—typically the ankle or calf—where sharks most often direct close‑range investigative approaches. The band houses the multi‑element neodymium array, conductive interfaces and hydrodynamic modulators within a flexible, marine‑grade polymer chassis. The architecture is intentionally asymmetrical to support field shaping and prevent uniformity in the resulting gradients, ensuring that sharks encounter inconsistent, non‑biological signals from any approach angle.

Neodymium Magnet Array

At the core of the system is a structured neodymium magnet array composed of primary high‑coercivity NdFeB magnets (N42–N52 grade) arranged to create steep, asymmetric magnetic gradients that generate the baseline irregular field detectable even when the wearer is stationary. Secondary micro‑magnets introduce interference zones that produce micro‑scale electric potentials when interacting with seawater, adding further complexity and unpredictability. The spacing between magnets is calculated to maximise gradient steepness while avoiding cancellation, and their orientation ensures that movement produces dynamic reconfiguration of interference patterns. Together, these elements form a multi‑directional, non‑uniform field generator unlike any existing magnetic deterrent.

Conductive and Semi‑Conductive Interfaces

To enhance electric‑field variability, Neograde incorporates marine‑grade stainless‑steel microplates, carbon‑loaded elastomers and graphitic polymer composites. These materials create dynamic resistance pathways when submerged, enabling fluctuating micro‑volt potentials, non‑linear field behaviour and movement‑dependent conductivity changes. This combination ensures that the field remains irregular, unstable and biologically ambiguous.

Hydrodynamic Modulators

The system includes small structural features designed to manipulate water flow, including microfins, turbulence ridges and flexible flow‑responsive tabs. These modulators generate micro‑eddies and ion‑rich vortices around the magnet array. As the wearer moves, these features distort the electric field in real time, increasing temporal variability and enhancing deterrent effectiveness.

Passive Field‑Shaping Geometry

The geometry of Neograde is engineered to prevent uniform field zones, maximise gradient steepness, ensure omnidirectional exposure and maintain stability during swimming. Key geometric features include asymmetric band curvature, offset magnet placement, variable‑thickness polymer housing and non‑concentric magnet alignment. These design choices ensure that sharks encounter inconsistent, non‑biological gradients regardless of approach angle.

Marine‑Grade Housing and Encapsulation

Because neodymium magnets are highly susceptible to corrosion, Neograde uses polyurethane or silicone over‑moulding, epoxy‑sealed magnet chambers, corrosion‑resistant stainless‑steel fasteners and UV‑stable elastomeric outer layers. The encapsulation thickness is optimised to balance magnetic performance with mechanical protection, ensuring long‑term reliability in marine environments.

Attachment and Fit System

Neograde employs a dual‑stage attachment system. The primary compression band is hydrophobic, quick‑drying and flexible, ensuring secure placement during dynamic movement. A secondary locking mechanism prevents slippage during surfing or diving and maintains consistent field orientation relative to the limb. The overall fit system minimises drag and maximises comfort during extended wear.

Advantages and Differentiators

The design and materials described above produce a set of advantages that distinguish Neograde from all existing shark‑deterrent technologies.

From a biological perspective, Neograde targets the sensory modality sharks rely on most at close range by disrupting electroreception during the final metres of an approach. The irregular gradients do not resemble prey muscle contractions, creating sensory ambiguity, and the chaotic field partially masks the swimmer’s natural bioelectric signature.

Operationally, Neograde requires no batteries, charging or electronics and is always active when submerged. It is maintenance‑free, with performance inherent to its materials and geometry, and it is environmentally neutral, producing no chemicals, acoustic emissions or electromagnetic pollution.

In terms of performance, the system provides orientation‑independent protection through its multi‑element array, while hydrodynamic modulators increase field irregularity during movement. Its effectiveness is consistent across environments and unaffected by turbidity, light conditions or battery temperature.

From a design standpoint, Neograde offers marine‑grade durability through corrosion‑resistant materials, a hydrodynamically stable form factor that minimises drag and a modular architecture that can be integrated into ankle bands, wetsuit cuffs, dive booties or surf leashes.

In the market context, Neograde represents a new category of shark‑bite mitigation: a passive neodymium‑based gradient disruptor distinct from both magnetic and electric devices. Its lack of electronics reduces manufacturing cost, increasing accessibility, and it is well suited for layered protection strategies by introducing a new sensory‑disruption pathway that complements electric deterrents.

Manufacturing, Cost Analysis and Economic Viability

The Neograde system is engineered for low‑complexity, high‑repeatability manufacturing, enabling scalable production at a fraction of the cost of electronic shark‑deterrent systems. Its passive architecture—built around a structured neodymium magnet array, conductive interfaces and hydrodynamic polymer components—allows for efficient assembly using established industrial processes. This section outlines the manufacturing workflow, material costs, assembly requirements, comparative cost positioning and the broader economic case for the innovation.

Manufacturing Overview

Neograde can be produced through a three‑stage manufacturing pipeline. The first stage involves preparing and encapsulating the neodymium magnets, including cutting and shaping both primary and micro‑magnets, applying corrosion‑resistant coatings and placing them into precision‑moulded chambers before over‑moulding with polyurethane or silicone. These steps rely on standard magnet‑handling and polymer‑moulding processes already common in consumer electronics and sporting‑goods production.

The second stage integrates the conductive and semi‑conductive interfaces. Stainless‑steel microplates are laser‑cut, carbon‑loaded elastomer inserts are injection‑moulded and both are positioned within the magnet housing using automated pick‑and‑place systems. Bonding is achieved through heat‑activated adhesives or ultrasonic welding, and the process requires no electronics, wiring or calibration. The third stage assembles the compression band, incorporating hydrodynamic features such as microfins, turbulence ridges and flexible tabs, and attaches the dual‑stage locking system. Final quality assurance includes tensile testing and immersion checks, using the same infrastructure employed for wetsuit cuffs, dive booties and surf leashes.

Material Cost Structure

At a production scale of 10,000 units, material costs remain exceptionally low. Primary NdFeB magnets account for approximately USD $2.50–$3.50 per unit, with secondary micro‑magnets adding $0.80–$1.20. Polymer over‑moulding contributes $1.00–$1.50, while stainless‑steel microplates and carbon‑loaded elastomers add modest additional costs. Hydrodynamic polymer components typically range from $0.50–$0.80, and the compression band with its locking system contributes $2.00–$3.00. Assembly and quality assurance add a further $1.50–$2.50, resulting in an estimated total manufacturing cost of USD $9.00–$13.00 per unit. This low cost is made possible by the absence of batteries, electrodes, circuitry, waterproof electronics, firmware or charging systems.

Manufacturing Scalability

Neograde is highly scalable due to its simple component geometry, lack of electronic calibration, compatibility with existing sporting‑goods manufacturing lines and minimal assembly steps. At production volumes exceeding 50,000 units, per‑unit costs could fall below USD $8.00. This scalability supports mass‑market adoption and positions Neograde as a viable option for large‑scale distribution.

Comparison to Existing Shark‑Deterrent Devices

Electric‑field deterrents such as the Ocean Guardian Freedom7 and Freedom+ Surf retail for USD $450–$650 and typically cost $120–$180 to manufacture due to batteries, capacitors, electrodes and waterproof electronics. They also face limitations related to battery dependence, orientation sensitivity and high retail pricing. Traditional magnetic deterrents, such as Sharkbanz, retail for $80–$120 with manufacturing costs of $12–$18, but their uniform fields limit gradient complexity. Neograde, by contrast, is projected to retail for $40–$70 with manufacturing costs of $9–$13, while offering movement‑amplified irregular gradients, no electronics, high scalability and a new sensory‑disruption pathway.

To clearly illustrate the advantages introduced by Neograde’s passive gradient‑disruption architecture, it is useful to compare its design, materials, mechanism of action, effective range, operational requirements, and cost profile with those of existing commercial shark‑deterrent technologies. The table below consolidates these attributes across all major device categories. This comparison highlights the narrow performance envelope of current technologies and demonstrates how Neograde occupies a distinct position in terms of biological alignment, simplicity, durability, and accessibility.

Together, these comparisons demonstrate that Neograde occupies a unique position in the shark‑deterrent landscape, combining biological alignment, passive operation, low cost, and durable materials in a way not achieved by any existing technology.

Cost–Benefit Profile

Neograde delivers a strong cost–benefit profile due to its low manufacturing cost, high durability and biologically aligned mechanism. It is approximately 90% cheaper to manufacture and 80% cheaper to purchase than electric deterrents, while still targeting the same sensory modality—electroreception. Because it contains no electronics, Neograde has zero operational costs, unlike electric systems that require battery replacement, charging cycles and electrode maintenance. Its marine‑grade polymers and sealed magnet chambers provide multi‑year durability, corrosion resistance and minimal wear, supporting long service life.

Lower retail pricing enables broad user adoption, including families, casual swimmers, surf schools and tourism operators. The system provides continuous protection with no maintenance, no charging and no environmental impact, creating a value proposition unmatched by any existing deterrent category.

Manufacturing Risk Assessment

A credible manufacturing plan must account for risks in materials, processes and supply chains. Neodymium magnet supply is subject to price fluctuations and geopolitical constraints, which can be mitigated by diversifying suppliers across China, Japan and the EU and maintaining buffer inventory. Polymer over‑moulding may introduce defects such as incomplete sealing or air bubbles, mitigated through automated injection moulding and in‑line X‑ray inspection. Bonding of conductive interfaces carries risks of delamination or corrosion, addressed through ultrasonic welding and corrosion‑resistant adhesives. Hydrodynamic components require precise moulding tolerances, best achieved with high‑precision steel tooling. Assembly variability can be reduced through automation and alignment jigs.

Supply Chain Considerations

NdFeB magnets are globally available from suppliers in China, Japan, Germany and the USA, though diversification is essential to reduce geopolitical exposure. Polymers such as TPU, silicone and neoprene have stable supply chains across the USA, EU, South Korea and Malaysia. Stainless steel and carbon‑loaded elastomers are commodity materials with predictable pricing. Assembly can be located in Southeast Asia for cost efficiency, Eastern Europe for quality‑focused production or Mexico for near‑shore access to US markets. Neograde’s lightweight, compact, non‑electronic and non‑hazardous nature significantly reduces shipping cost and regulatory burden compared to battery‑powered devices.

Summary

The Neograde system’s manufacturing and cost structure provide a strong economic foundation. It offers simple, scalable production using existing industrial processes, low per‑unit cost driven by its passive architecture, high durability through marine‑grade materials and retail pricing far below electric deterrents. It represents a new category of shark‑bite mitigation that is both effective and accessible, with strong margins, low operational costs, manageable manufacturing risks and a stable, diversified supply chain. These factors position Neograde as the first shark‑deterrent technology capable of true mass‑market adoption across recreational, commercial and tourism sectors.

Performance Expectations, Limitations and Optimal Deployment Contexts

The Neograde system is engineered to reduce the likelihood of a shark bite by disrupting the electroreceptive cues sharks rely on during the final stages of an approach. Its performance is driven by the passive neodymium‑magnet architecture, movement‑amplified gradient generation and the biologically anomalous field patterns described earlier. While Neograde offers several performance advantages, it is not a guarantee of safety. This section outlines the expected performance envelope, inherent limitations and the environments where the system is most effective.

Expected Performance

Neograde is optimised for the critical one‑to‑two‑metre zone where sharks rely heavily on electroreception to confirm prey identity. Within this range, the system generates steep electric‑field gradients, irregular non‑biological patterns and movement‑amplified fluctuations. These characteristics are expected to increase hesitation, reduce investigative contact and lower the probability of a committed bite. Performance is highest when the wearer is moving—swimming, kicking, paddling, finning or treading water—because movement increases the complexity of the field. This aligns with shark behaviour, as sharks typically approach moving targets.

The multi‑element magnet array and passive field‑shaping geometry provide omnidirectional protection, ensuring that sharks approaching from below, behind or laterally encounter the same irregular field signature. Neograde is also robust across environmental conditions, remaining unaffected by water clarity, turbidity, light levels, temperature or battery depletion. Because it contains no electronics, it operates continuously whenever submerged, with no switches, charging cycles or electronic failure modes.

Expected Behavioural Outcomes in Sharks

Based on the mechanism of action and the scientific literature on shark electroreception, Neograde is expected to produce hesitation, increased circling distance, aborted close‑range investigations, reduced likelihood of bumping or test biting and avoidance of the lower limbs where the system is worn. These outcomes mirror behavioural patterns observed in studies of electric deterrents, though Neograde achieves them through a passive mechanism.

Species‑Specific Considerations

Performance may vary depending on species, individual temperament, motivational state and environmental context. Sharks with highly developed electroreception, such as hammerheads, may be more sensitive to irregular gradients, while opportunistic feeders may be less deterred. Conditions such as baited environments or competitive feeding may also reduce effectiveness.

Limitations

Neograde is not a risk‑elimination device. No shark‑deterrent technology—electric, magnetic, chemical, visual or acoustic—can eliminate the risk of a shark bite. Its effective range is limited to approximately one to two metres, meaning sharks approaching at high speed or from beyond this distance may not be influenced until the final moments. Individual sharks may vary in their tolerance to irregular electric fields, and performance is reduced when the wearer is stationary, as movement amplifies gradient complexity. Neograde does not replace situational awareness, local safety guidelines, lifeguard instructions or SharkSmart programs. The neodymium array may also interact with metal equipment such as dive knives, buckles or magnetic compasses.

Optimal Deployment Contexts

Neograde performs best in environments where sharks rely heavily on electroreception during the final metres of approach. High‑visibility, low‑turbulence waters provide ideal conditions, as do recreational swimming and snorkelling zones where limb movement is predictable and close‑range encounters are more common. Surfing and bodyboarding also align well with Neograde’s strengths, as continuous leg movement enhances gradient irregularity and sharks often approach from below or behind—angles where omnidirectional protection is advantageous.

Shallow reef systems, where reef sharks depend strongly on electroreception, are another favourable context. Neograde’s passive, maintenance‑free and durable design makes it well suited for tourism and rental environments, including snorkel tour operators, surf schools, lifeguard services and marine‑park visitors. It is particularly effective in regions with moderate shark presence but low aggression, such as non‑baited and non‑feeding contexts.

Summary of the Performance Envelope

Neograde is expected to reduce the likelihood of a close‑range bite, disrupt shark electroreception within one to two metres, perform consistently across environmental conditions, provide omnidirectional movement‑amplified protection and operate continuously without power. However, it cannot eliminate risk, has a limited effective range, may vary in effectiveness across species and individuals and performs best during movement. This integrated performance profile reflects the realities of shark sensory biology and the constraints of passive deterrent technologies.

Conclusion

The development of the Neograde passive neodymium‑based gradient disruption system represents a significant advance in shark‑bite mitigation technology. By aligning its design with the biological principles that govern shark electroreception, the system introduces a new sensory‑disruption pathway that differs fundamentally from both magnetic and electric deterrents. Its structured neodymium‑magnet architecture, combined with conductive interfaces and hydrodynamic modulators, produces irregular, movement‑amplified electric‑field gradients that sharks are not adapted to interpret. This mechanism targets the precise sensory modality used during the final metres of an investigative approach, where risk is highest.

Neograde’s passive operation, omnidirectional protection and environmental robustness make it well suited to recreational, tourism and moderate‑risk marine environments. Its low manufacturing cost, scalable production and absence of maintenance requirements position it as the first deterrent with genuine mass‑market potential. Unlike electronic systems, which depend on batteries, electrode spacing and user compliance, Neograde provides continuous protection whenever submerged, placing no operational burden on the wearer.

At the same time, the system’s limitations must be recognised. Neograde is not a risk‑elimination tool, nor can it influence sharks beyond its effective range of approximately one to two metres. Species‑specific and individual behavioural variability will always influence outcomes. The system is best understood as a risk‑reduction measure—one that complements, rather than replaces, situational awareness, local guidelines and established safety practices.

Taken together, Neograde offers a compelling combination of biological alignment, engineering simplicity, economic accessibility and practical usability. It fills a long‑standing gap between low‑cost but biologically weak magnetic devices and high‑cost, high‑maintenance electric deterrents. By introducing a new category—the passive neodymium‑based gradient disruptor—the system expands the toolkit available to swimmers, surfers, snorkellers and marine‑tourism operators seeking to reduce shark‑bite risk without compromising comfort, mobility or affordability.

The next phase of development involves prototype construction, controlled‑environment testing and field validation to quantify behavioural responses across species and contexts. These efforts will refine the system’s geometry, magnet configuration and hydrodynamic features, ensuring reliable and repeatable performance in real‑world conditions.

This innovation demonstrates that meaningful improvements in ocean safety do not require complex electronics or high‑energy systems. Instead, they can emerge from a deep understanding of biological systems, material science and hydrodynamic behaviour—an approach that opens new pathways for future research and product development in marine‑safety technologies.

References

Adams K.R.et.al.(2020). Coexisting with sharks: a novel, socially acceptable and non-lethal shark mitigation approach. Sci Rep.Oct 15;10(1):17497. https://doi.org/10.1038/s41598-020-74270-y
 
Bradshaw C.J et.al. (2021) Predicting potential future reduction in shark bites on people. Royal Society open science 8:201197. https://doi.org/10.1098/rsos.201197

Caldicott D.G., et.al. (2001) The anatomy of a shark attack: a case report and review of the literature. Injury 32:445-453. https://doi.org/10.1016/s0020-1383(01)00041-9

Clarke, T. M. et. al. (2022). Effectiveness of commercially available personal electric shark deterrents on tiger sharks (Galeocerdo cuvier). Final Report to Queensland Department of Agriculture and Fisheries, 53 pp. (Official PDF link — publicly accessible). https://www.publications.qld.gov.au/ckan-publications-attachments-prod/resources/3170e527-2cea-440a-9875-c327de9582d6/electric-shark-deterrents-report.pdf?ETag=876adfc8322818222283327a1fa0787f

Cliff G. (1991). Shark attacks on the South African coast between 1960 and 1990. South African Journal of Science 87:513-518. https://journals.co.za/doi/pdf/10.10520/AJA00382353_7199
 
Curtis T.H. et.al. (2012). Responding to the risk of White Shark attack. Global Perspectives on the Biology and Life History of the White Shark CRC Press:477-510. https://www.semanticscholar.org/paper/Responding-to-the-Risk-of-White-Shark-Attack%3A-and-Curtis-Bruce/753c38224dba87f306038886931d46975cb4f47b
 
Gauthier A. et.al. (2020). Variable response to electric shark deterrents in bull sharks, Carcharhinus leucas. Scientific reports 10:1-13. https://doi.org/10.1038/s41598-020-74799-y
 
Gray G.M. and Gray C.A. (2017). Beach-user attitudes to shark bite mitigation strategies on coastal beaches; Sydney, Australia. Human Dimensions of Wildlife 22:282-290. https://doi.org/10.1080/10871209.2017.1295491
 
Harahush, B. & Mcphee, D.. (2016). Global shark attack hotspots: Identifying underlying factors behind increased unprovoked shark bite incidence. Ocean & Coastal Management. 133. 72-84. 10.1016/j.ocecoaman.2016.09.010. https://doi.org/10.1016/j.ocecoaman.2016.09.010
 
Hart N.S. and Collin S.P. (2015). Sharks senses and shark repellents. Integrative zoology 10:38-64. https://doi.org/10.1111/1749-4877.12095
 
Hueter et.al. (2004). Sensory biology of elasmobranchs. Biology of sharks and their relatives:325-368. https://faculty.lsu.edu/maruskalab/files/publications/06_sensory_biology_of_elasmobranchs.pdf
 
Huveneers C. et. al. (2012). Effects of the Shark ShieldTM electric deterrent on the behaviour of white sharks (Carcharodon carcharias). Final Report to SafeWork South Australia. SARDI Publication No. F2012/000123–1. SARDI Research Report Series No. 632. Adelaide: SARDI - Aquatic Sciences. https://www.researchgate.net/publication/261562759_Effects_of_the_Shark_Shield_electric_deterrent_on_the_behaviour_of_white_sharks_Carcharodon_carcharias

Huveneers C. et.al. (2013). Effects of an electric field on white sharks: in situ testing of an electric deterrent. PloS one 8:e62730. https://doi.org/10.1371/journal.pone.0062730

Huveneers, C. et al. (2018). Effectiveness of five personal shark‑bite deterrents for surfers. PeerJ, 6:e5554. https://peerj.com/articles/5554/

Kempster R.M. et al. (2016). How close is too close? The effect of a non-lethal electric shark deterrent on white shark behaviour. PLoS One 11:e0157717. https://doi.org/10.1371/journal.pone.0157717

McPhee D. (2012). Likely effectiveness of netting or other capture programs as a shark hazard mitigation strategy in Western Australia. Department of Fisheries, Western Australia. https://library.dpird.wa.gov.au/cgi/viewcontent.cgi?article=1026&context=fr_fop

McPhee D (2014) Unprovoked shark bites: are they becoming more prevalent? Coastal Management 42:478-492. https://doi.org/10.1080/08920753.2014.942046

McPhee D.P. et. al. (2021). A comparison of alternative systems to catch and kill for mitigating unprovoked shark bite on bathers or surfers at ocean beaches. Ocean & Coastal Management 201:105492. https://researchers.mq.edu.au/en/publications/a-comparison-of-alternative-systems-to-catch-and-kill-for-mitigat/

Midway S.R. et.al.(2019). Trends in global shark attacks. 14:e0211049. https://doi.org/10.1371/journal.pone.0211049

Riley M. et. al. (2022). The Australian Shark-Incident Database for quantifying temporal and spatial patterns of sharkhuman conflict. Scientific data 9:1-9. https://doi.org/10.1038/s41597-022-01453-9
 
Rosciszewski-Dodgson M.J. and Cirella G.T. (2021.) Shark bite survivors advocate for non-lethal shark mitigation measures in Australia. AIMS Environmental Science 8:567-579. https://doi.org/10.3934/environsci.2021036
 
Ryan L.A. (2019). Environmental predictive models for shark attacks in Australian waters. Marine Ecology Progress Series 631:165-179. https://www.jstor.org/stable/26920563
 
Simmons P. et. al. (2021). A scenario study of the acceptability to ocean users of more and less invasive management after sharkhuman interactions. Marine Policy 129:104558. https://doi.org/10.1016/j.marpol.2021.104558
 
Thiele M. et.al. (2020). Response of blacktip reef sharks Carcharhinus melanopterus to shark bite mitigation products. Scientific reports 10:1-12. https://doi.org/10.1038/s41598-020-60062-x

West, J. (2011). Changing patterns of shark attacks in Australian waters. Marine and Freshwater Research. 62. 744-754. https://doi.org/10.1071/MF10181

If you’re interested in this idea, I would be glad to hear from you.

Share this page

Licence: All ideas and concepts shown on this website are shared under the Creative Commons Attribution 4.0 International Licence (CC BY 4.0) . You are free to use, adapt, and build upon them, provided you give appropriate credit to Dr. Patrick Reynolds and include a link to this website.
© 2026 Patrick Reynolds