Open marine hardware
Sailing robots, ocean drones and the sensors aboard
Protei documents open-source marine technology in plain words — build notes, gear guides and honest reviews of the hulls, rigs and instruments that go to sea.
Sailing robots
Wind-driven hulls and ocean drones: rigs, steering, power and what a long swell does to all three.
Read the notes →Sensing hardware
Environmental sensing kit aboard small craft — mounting, logging, drift and the calibration that keeps it honest.
Read the notes →From the workshop
What gets documented here is the part that usually happens off camera: the hull that leaked, the sensor that drifted, the fix that held through a second day of swell. Parts are named, methods are described in the order things actually happened, and the failures worth repeating are left in.
Go to the latest notes →Just off the bench
Latest from the water
Newest write-ups first — sea trials, teardowns and the gear that earns its place aboard.
LoRa vs WiFi for Boat Telemetry: A Practical Guide (2026)
LoRa vs WiFi for boat telemetry compared on range, power, data rate and reliability, with verdicts for moored, marina, coastal and offshore…
How Waypoint Navigation Works on Sailing Robots (October 2026)
How waypoint navigation works on a sailing robot in : route definition, position fixes, cross-track error, arrival radius, wind handling, safety rules…
How to Plan a Waypoint Route for a Drone Boat, Step by Step 2026
How to plan a waypoint route for a drone boat: set mission limits, read the chart, spot hazards, budget endurance, and set…
How to Tune a PID Controller for a Boat Rudder (2026)
How to tune a PID controller for a boat rudder in : set Kp first, add derivative damping, then integral, and prove…
What Is PID Control in Simple Terms? A Guide (2026)
Learn what is PID control in simple terms: how the P, I and D terms work together, and why makers use them…
How to Calibrate a Magnetometer on a Boat (October 2026)
Learn how to calibrate a magnetometer on a boat, correct hard- and soft-iron distortion, set heading, and verify accuracy safely before sea…
How to Build a Digital Compass for a Boat (2026): Proven Guide
How to build a digital compass for a boat in : pick a 9-axis IMU, mount it clear of the engine, wire…
How to Read NMEA Sentences: A Marine Tech Guide (2026)
Learn how to read NMEA sentences in : decode talker IDs, split comma-separated fields, validate XOR checksums and convert coordinates, with worked…
How IMU Sensors Work in 2026: A Marine Robotics Guide
How IMU sensors work explained simply: accelerometers, gyroscopes, sensor fusion, calibration, and picking a sensor for sailing robots and ocean drones in…