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.
How to Prevent Thermal Runaway in Battery Packs (October 2026)
Learn how to prevent thermal runaway in battery packs () with chemistry-aware design, fusing, monitoring, staged validation and a safe incident response…
How to Store Lithium Batteries Safely: 9 Proven Tips (2026)
How to store lithium batteries safely in : temperature bands, charge levels, terminal protection, the right container, and what to do with…
How Electric Outboards Compare to Gas: Range and Costs (2026)
How electric outboards compare to gas for range, power, charging, upkeep and noise – with real owner range figures and a checklist…
How to Make a Curved Flexible Hull for Small Boats (2026)
Learn how to make a curved flexible hull for small boats or marine robots in , with practical forming, reinforcing, sealing and…
How to Choose a Propeller for a Small Electric Boat (2026) Guide
A step-by-step guide to how to choose a propeller for a small electric boat in : match diameter, pitch and blade count…
How to Estimate Range for an Electric Boat (October 2026)
Learn how to estimate range for an electric boat in using usable battery kWh, power draw at your cruising speed, currents, weather…
How to Test Drag on a Model Hull: Simple Tank Setup 2026
Learn how to test drag on a model hull with a controlled tank method, repeatable runs, and practical fixes for small boats.…
How Flexible Hulls Move Through Water: A Practical Guide (2026)
How flexible hulls move through water, explained plainly: added mass, wave response, drag, stability, and the stiffness trade-off for marine robots in…
How to Measure Boat Speed Without GPS (2026)
Learn how to measure boat speed without GPS in using a stopwatch over a measured mile, a chip log, a pitot tube,…