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 Choose Outboard Shaft Length: Simple Guide (2026)
How to choose outboard shaft length in : measure your transom height, check the manufacturer's approved range, and match the motor to…
Why Is My Outboard Not Peeing Water? Causes & Fixes (2026)
Why is my outboard not peeing water? Clogged telltale, blocked intake or a failed impeller, plus safe checks to try before calling…
How to Put Registration Numbers on a Boat: A Clear Guide 2026
How to put registration numbers on a boat in : step-by-step vinyl and paint application, correct placement, and the local rules to…
How to Clean an Outboard Carburetor: Safe Step-by-Step Guide 2026
How to clean an outboard carburetor safely in : drain fuel, clear every passage, set float height, fit new gaskets and leak-test…
How to Remove Old Boat Registration Numbers (2026)
How to remove old boat registration numbers in : confirm the old number is obsolete, prep the hull, lift the vinyl decal…
How to Paint an Aluminum Boat: Proven Prep and Coating 2026
Learn how to paint an aluminum boat in : cleaning, abrasion, etching, primer, thin topcoats and correct cure times for a finish…
How to Get Rust Stains Off a Boat Hull: Proven Steps (2026)
How to get rust stains off a boat hull in : identify the surface, find the corroding hardware, treat gelcoat with oxalic…
How to Get Mildew Off Boat Seats: Simple Steps (October 2026)
How to get mildew off boat seats in : start with vinegar, step up to a marine cleaner, use diluted bleach only…
How to Clean Boat Vinyl Seats: Easy Guide 2026
Learn how to clean boat vinyl seats in : remove salt, sunscreen and mildew stains, dry and condition the vinyl, and skip…