Rheo Dive

Rheo Dive is the world’s first patented smart dive mask — a fully integrated heads-up display and dive computer built into a scuba mask. Real-time depth, dive time, air consumption, compass heading, NDL, safety stops, ascent rate, and GPS — projected directly into the diver’s field of view. No wrist checks. No head movement. No distraction.

This is not a screen bolted to a mask frame. It is a precision optical system with custom electronics, custom firmware, custom silicone tooling, and a companion iOS app — engineered from a blank page to a mass-producible product.

We own the entire product. CTO role from concept.

The idea

The concept came from a real problem observed during Finger Lakes diving: constantly looking down at a wrist-mounted dive computer breaks situational awareness, forces head movement that disturbs buoyancy, and creates a dangerous habit of splitting attention between the environment and the instrument.

Every existing solution — wrist computers, console gauges, even the few HUD products that have been attempted — requires the diver to look away from what they’re doing. The question was simple: what if the data was just there, always visible, in a minimal overlay that stays out of the way until you need it?

No product on the market did this properly. The few HUD attempts were bulky aftermarket clip-ons with poor optics, limited data, and no integration with the mask itself. Nobody had built a ground-up smart dive mask where the HUD, the dive computer, the optics, the mask, and the companion software were designed as a single system.

So we built one.

From idea to product — the full path

This is a textbook 0→1 hardware product development, running the full engineering lifecycle:

Every stage required decisions that compound. Get the optics wrong in POC and EVT is wasted. Get the silicone skirt geometry wrong in EVT and DVT mold tooling is scrap. Get the PCBA layout wrong in DVT and PVT is a board spin. The only way to run this without burning money is to make the right architecture decisions early and validate the highest-risk elements first.

Custom optics

The optical system is the hardest part of this product. You’re projecting data onto a lens surface that the diver is looking through — at a reef, at a buddy, at a wreck. The HUD data needs to be readable without being distracting. It needs to work in tropical sunshine at 3 meters and in low-visibility cold water at 40 meters. And it needs to fit inside a mask form factor that’s comfortable for hours of diving.

Off-the-shelf display modules couldn’t do this. The optical requirements — focal distance, ambient light rejection tuned for underwater color spectra (blue-green dominant), minimal parallax, compatibility with prescription lens inserts, ghosting suppression at the projection interface — demanded a purpose-built optical assembly.

We designed a custom optical path using a micro-display and collimating lens assembly. The projection system maintains readability from close focus to infinity, with the HUD information positioned just outside the direct line of sight — visible when you glance at it, invisible when you don’t. Multiple prototype iterations resolved chromatic aberration and ghosting at the waveguide interface.

Custom PCBA

The electronics had to do everything a full dive computer does — sensor fusion, decompression calculations, display driving, GPS, compass, wireless communication, battery management — on a board small enough to fit inside a dive mask frame with power consumption low enough for 25+ dives per charge.

The custom PCBA integrates:

The entire board is designed as low-SWaP (Size, Weight, and Power) — because every gram matters in a mask that sits on your face for a 90-minute dive, and every milliwatt determines whether you get 15 dives or 25 dives per charge.

Custom display

The display is not an OLED panel or an LCD screen. It’s a micro-display driven through a custom optical path that projects information onto the mask lens. The rendering pipeline runs on the main MCU — no separate GPU. Pre-rendered glyph tables for dive data, direct framebuffer writes for consistent frame timing, and a rendering architecture that prioritizes power efficiency over pixel count.

The HUD shows what matters:

Nothing extra. No fish identification. No social features. The data a diver actually needs, always visible, never in the way.

Custom silicone skirt

A dive mask is only as good as its seal. The silicone skirt — the soft part that contacts the diver’s face — determines comfort, fit, and whether the mask leaks at depth. This is where most “smart mask” concepts fail: they try to cram electronics into a standard mask body without accounting for how the added weight, volume, and geometry change the skirt geometry and seal characteristics.

We designed custom silicone skirt tooling from scratch. The skirt form is engineered around the electronics package — the weight distribution, the center of gravity shift from the PCBA and optics, and the modified frame geometry all factor into the skirt profile. The silicone compound, shore hardness, and skirt lip geometry were iterated to maintain a reliable face seal across different face shapes despite the non-standard mask frame.

The skirt is designed as a replaceable component — sustainable design that extends product life without discarding the electronics.

iOS companion app

The mask is half the product. The other half is the Rheo Dive Electronic Dive Log app — a native iOS application we built from scratch.

The app handles everything that happens before and after the dive: configuration, dive planning, log review, and data visualization. Dive logs sync wirelessly from the mask over BLE. GPS tracks are displayed on maps. Dive profiles are rendered with depth, time, temperature, and decompression data. Settings — display brightness, data layout, alert thresholds, units — are all configured from the app and pushed to the mask firmware.

The app isn’t an afterthought bolted onto a hardware product. The firmware communication protocol, the data model, and the app architecture were designed together from the start. The mask and the app share a common data schema — there’s no translation layer, no adapter code, no impedance mismatch between what the mask records and what the app displays.

Dive computer firmware

Underneath the HUD is a full dive computer. This isn’t a depth gauge with a timer — it’s a decompression computer that implements real-time deco models, tracks tissue loading across multi-dive days, calculates no-decompression limits, manages safety stop logic, and handles the alert hierarchy that keeps divers safe.

The firmware architecture is layered:

• Real-time sensor layer — pressure, IMU, compass, temperature sampling at consistent rates with hardware-triggered ADC conversion
• Dive computer engine — decompression model, tissue compartment tracking, NDL calculation, ascent rate monitoring, safety stop state machine
• Display renderer — HUD composition, glyph rendering, power-managed display refresh
• Communication layer — BLE stack, dive log serialization, OTA firmware update support
• Power manager — battery SOC estimation, cold-weather compensation, dive-mode power profiling, wireless charge management

Single codebase. The firmware architecture supports hardware variant management through compile-time configuration — the same code drives different board revisions without forking.

The engineering underneath

A few things that define the quality of this product:

Underwater optics are hard. Water changes the refractive index of everything. A HUD that’s readable in air may be invisible underwater. The optical path was designed and validated for underwater viewing conditions from the start — not adapted from an air-optical design. Multiple prototype iterations in actual diving conditions (not a lab tank) were required to get the projection clarity, brightness, and contrast right.

Pressure changes everything. At 40 meters depth, ambient pressure is 5 atmospheres. Every seal, every connector, every component junction is under pressure. The PCBA conformal coating, the display window bonding, the battery compartment seal, the button mechanisms — all designed for sustained pressure exposure, not just a static pressure test.

Thermal extremes. The mask needs to work in 4°C North Atlantic water and 32°C tropical water. Battery chemistry, display response time, sensor accuracy, and silicone flexibility all change with temperature. The firmware includes temperature compensation for every sensor, and the power management adjusts discharge curves based on real-time temperature measurement.

Wearable ergonomics. This isn’t a wrist device. It sits on the diver’s face for 60–90 minutes. Weight distribution, strap loading, nose bridge pressure, field of view obstruction — all of these were iterated through multiple EVT builds with actual divers in actual water. The electronics package had to shrink until it disappeared into the mask frame.

Timeline

Built for the field

Who it’s for

What this demonstrates

This is what full-stack hardware product development looks like when one team owns everything.

Optics, PCBA, firmware, mechanical, silicone tooling, iOS app, BLE protocol, dive computer algorithms, display rendering, power management, GPS integration, industrial design, DFM, patent filing — all from one engineering team, all designed as a coherent system, all moving through POC → EVT → DVT → PVT → MP without the integration disasters that happen when five different contractors build five different subsystems and nobody owns the whole thing.

The Rheo Dive mask exists because every decision — from the optical path to the silicone shore hardness to the BLE packet format — was made by people who understood the full system. That’s how you build a product that works underwater, on your face, for 90 minutes, and doesn’t leak, doesn’t fog, doesn’t crash, and shows you exactly what you need to see exactly when you need to see it.