A Simple GPS Solution for Small Boats

Being a marine pilot for more than a decade, I never thought I would need to create a product like this. But over the past two years, during ship pilotage in Baltic sea port, GPS spoofing has become a serious issue. Sometimes nearly 80% of incoming vessels experience GPS problems — from unstable signals to total loss of GPS. This is a direct safety concern.

I started searching for solutions. Inspired by ChatGPT suggestions, I tested different external GPS receivers, shielding, and navigation apps. First I tried with devices like the Qstarz, but realized that 2-constellation GPS receiver (GPS and Glonass) is not anymore acceptable in modern navigation.

Then I tested RaceBox units. (25Hz GNSS Module Simultaneous tracking of GPS, Glonass, Galileo, Beidou, SBAS, QZSS) They worked better outdoors with shielding, but existing connector apps caused problems — apps like NV Charts froze, while SeaPilot showed “jumping” course and speed.

I contacted NV Charts and RaceBox support, but received no real solution. RaceBox didn’t want to adapt their app for marine navigation users. So with the help of ChatGPT and a developer, I created RaceBox Injector: a simple, affordable app that connects RaceBox devices to Android navigation apps, with an optional smoothing filter (3–5 seconds) to stabilize COG and SOG.

After 50+ hours of testing, I confirmed: NV Charts works smoothly with RaceBox, SeaPilot is stable with smoothing enabled, and the setup even rivals professional units. It’s not a final solution against spoofing, but it’s an important step.

During testing, RaceBox Injector proved that affordable consumer hardware can be adapted for reliable backup navigation. This inspired a new idea:

Imagine a compact, waterproof RaceBox (or similar 4-constellation GPS receiver) placed on deck, powered by a small battery, and streaming stable GPS data continuously to an Android phone via Bluetooth. With RaceBox Injector providing smoothing and injection, any navigation app (NV Charts, OpenCPN, Orca, SeaPilot, etc.) could instantly switch to this external GPS source whenever needed.

Such a setup could become a low-cost backup navigation system for small boats, yachts, and fishing vessels — offering more stability and resilience compared to relying solely on built-in smartphone GPS.

Please check entire “project” with Racebox Micro.

Parts:

Racebox Micro.

Waterproof junction/mounting box

USB C cable. The color of the wires inside usually tells you what they do.
Here’s the standard breakdown you’ll typically see if you strip open a cable: Red → +5 V, Black → Ground (GND), Green → Data+ (D+),White → Data− (D−)

Power bank or a battery pack