NautiSafe

The Problem

Deciding whether it's safe to go to sea is not a simple question. It depends on who you are (a recreational boater on a 5-meter dinghy or a fisherman on a 10-meter vessel), where you want to go, what the weather forecast says for the next few hours, and how that specific boat handles in the expected conditions. I couldn't find an integrated system that combined all these factors in real time on board.

Traditional nautical systems are expensive, proprietary, and show raw data: wind speed, wave height, forecasts. Interpretation is left to the captain. For commercial and charter boats this creates legal liability: if you set out and something goes wrong, who authorized the departure?

The Solution

I designed a risk assessment algorithm combining four layers of data: the boat's CE category (determines the maximum sea state it's certified for), the hull's structural characteristics (stability, draft, engine power), real-time marine weather and hourly forecasts along the planned route, and live sensor readings from onboard instruments via NMEA 2000.

NMEA 2000 is the maritime standard for communication between onboard instruments. Data reaches the tablet over Bluetooth Low Energy, with low latency and low power draw. The system reads the engine sensors, GPS, anemometer and the other instruments installed on board.

The architecture is offline-first by necessity: in open water there's no connection. Nautical vector charts are downloaded and cached before departure using a predictive loading system based on the planned route. Bathymetry, hazard points, refuge ports: all available without internet. When the boat returns to port, the system syncs logs and updates.

The app is built with React Native and Expo.

The Result

The app was completed and tested with real NMEA 2000 data. It gives the captain an understandable risk index with specific reasons, not just a green or red light. Navigation with vector charts and bathymetric overlays is integrated into the same interface.