Hydreon
Ride the water. Your way.
Two self-contained boat hulls under your feet. Eight vectoring thrusters, a 500 Hz active stability system and verified semi-planing lift carry you across open water — no boat, no tow rope, no crowd.
- 8.5kts
- Top speed
- 60min
- Ride time
- 8×
- Vectoring thrusters
- 500Hz
- Stability loop
It's 6:30 PM.
Where do you run?
Thousands of people have just finished work. Some are running along the Tseung Kwan O waterfront. Some are cycling. Some are playing football. They're all looking for the same thing — space.
Running tracks are crowded. Sports facilities are fully booked. Cycling lanes are congested. Up to 10,000 runners share the waterfront each evening — leaving each person an average of just 2–3 m² of usable space. High density, real risk of collision.
Yet right beside them lies something enormous, completely open, and almost entirely unused.
The water.
Stand on the Cross Bay Bridge in Tseung Kwan O and you can see kilometers of open water in every direction. Current utilization is less than 2%. Roughly 98% of potential training space is untapped.
So we asked: why are we fighting for space on land when an entirely new sporting environment already exists beside our cities?
Each shoe is a boat.
A self-contained 58 cm hull with its own thrusters, battery and flight controller under each foot. Tap a marker to explore the architecture.
A sharp-bow ship hull in carbon-reinforced marine PVC/PC. 58 × 26 cm per shoe with a 28–31 cm draft for extended-depth stability.
The math that holds you up.
Every load-bearing number on this page has been checked against first principles — buoyancy, planing lift, thruster momentum theory and control bandwidth. Where the early concept overreached, we corrected it. What's published here is the feasible design.
Static buoyancy — verified
Each shoe carries 10 kg of hardware, which needs 10 L of displacement to float. The hull encloses 20–25 L of sealed nitrogen chambers — a 2.0–2.5× safety factor. If you step off, your Hydreon floats. By design, it does not float you standing still: that's what speed is for.
Dynamic lift — verified
In semi-planing, lift follows L = ½ρv²·S·C_L with 0.30 m² of wetted planing area across the pair and C_L ≈ 0.40 for the V-hull, plus ~25 kg of residual buoyant support. A 75 kg rider is fully carried near 6.8 kts; 95 kg near 7.7 kts.
Thrust & power — corrected
Eight 90 mm ducted vectoring thrusters (four per shoe) deliver 25 N each at a 350 W burst — conservative against momentum theory. Cruise draws ~470 W per shoe, so the swappable 24V/25Ah (600 Wh) packs hold the 10 kg-per-shoe mass budget and still give 45–70 minutes.
Stability software — verified
A 200 Hz extended Kalman filter fuses IMU, water-pressure and GPS data. A 200 Hz attitude loop commands a 500 Hz rate loop and mixer, with T ∝ ω² thrust linearization and gain scheduling by speed. Prediction compensates the 100–250 ms thruster latency — the true bandwidth bottleneck.
Lift vs speed — L = ½ρv²·S·C_L
S = 0.30 m² · C_L = 0.40| Speed | m/s | q (Pa) | Lift (N) | Supports (kg) |
|---|---|---|---|---|
| 4 kts | 2.06 | 2,120 | 254 | 25.9 |
| 5 kts | 2.57 | 3,308 | 397 | 40.5 |
| 6 kts | 3.09 | 4,764 | 572 | 58.3 |
| 7 kts | 3.60 | 6,484 | 778 | 79.3 |
| 8 kts | 4.12 | 8,469 | 1,016 | 103.6 |
Plus ~25 kg of residual buoyant support in semi-planing. A 75–95 kg rider is carried at 7–8.5 knots (≈ 4 m/s cruise).
Operating modes
Hydrodynamic lift takes over your weight. Balanced gains, best efficiency — this is where you live.
The intelligence that keeps you up.
Eight thrusters. One mind.
Four 90 mm ducted thrusters sit at the corners of each hull, each vectoring through 360° independently. Differential thrust gives the controller direct authority over roll, pitch and yaw — like a drone, but on water.
Safe by design. Powered all day.
Swappable 24V / 25Ah sealed packs
One IP67-sealed 600 Wh pack rides inside each hull, right-sized to keep every shoe under its 10 kg mass budget so buoyancy always holds. Tool-free swaps in seconds deliver 45–90 minutes of ride time per charge.
Auto shutoff & fail-safe
Fall detection, geofence and speed limits cut thrust instantly, and a magnetic kill-leash stops all eight thrusters the moment you separate.
Hardware always floats
Sealed dual-nitrogen chambers give a 2.0–2.5× buoyancy reserve, so a dropped shoe returns to the surface every time.
Wireless throttle
An ergonomic handheld remote controls speed and mode with a precise, waterproof trigger and haptic feedback.
Your new way to move across the water.
Glide the coastline
Chase the sunset
Go where boats can't
Every number, dialed in.
Performance
- Cruise speed
- 4–8 kts (≈ 7.5–15 km/h)
- Top speed
- ~8.5 kts
- Supported rider
- 75–95 kg
- Thrusters
- 8 × 25 N (4 per shoe)
- Peak system thrust
- 200 N
Power
- Battery
- 24V / 25Ah (600 Wh) per shoe
- Water rating
- IP67 sealed, swappable
- Ride time
- 45–90 min (mode dependent)
- Cruise draw
- ~470 W per shoe
- Charge time
- ~90 min (fast charger)
Intelligence & safety
- State estimation
- 200 Hz extended Kalman filter
- Attitude / rate loop
- 200 Hz / 500 Hz
- Thrust model
- T ∝ ω², gain-scheduled
- Actuator latency
- 100–250 ms (predicted out)
- Fail-safe
- Fall detect · geofence · kill-leash
Build & buoyancy
- Hull dimensions
- 58 × 26 cm, 28–31 cm draft
- Deck height
- 5–10 cm above water
- Buoyancy reserve
- 20–25 L/shoe (SF 2.0–2.5)
- Shell
- Carbon-reinforced marine PVC/PC
- Hardware mass
- ~10 kg per shoe
Your water mobility OS — in your pocket
Live telemetry, GPS navigation in Sai Kung open water, crew location sharing, pro tuning, and session analytics — the full Hydreon companion experience, localized in six languages.
Five tabs. One connected ride.
- Dashboard — speed, battery, RPM, IMU stance & E-STOP
- Map & GPS — Sai Kung route, destination ETA & friend pins
- Social — share location, meet-up points & activity feed
- Tuning — drive modes, IMU deadband & BLE diagnostics
- Profile — session stats, achievements & language picker
Use the language menu in the header — the app preview matches your selected locale.
Build your Hydreon.
Add accessories
Reserve with a refundable $200 deposit · Ships Q3 2026
Shape the final prototype.
We're building Hydreon for riders worldwide. Your input decides what we build — and reserves your early-access slot.
First — how do you ride?
98% of the water is empty. Take it.
Join the global beta waitlist in 2 minutes — share your input and reserve early access to Hydreon.
Questions, answered.
Still curious? Our team is here to help you get on the water. Contact support →
Not much. The active stability system runs a 200 Hz state estimator and a 500 Hz rate loop that vector all eight thrusters to hold you upright, so Launch mode does most of the balancing while you build speed. We recommend starting in calm, flat water — most riders are cruising within a session.