Watt & Sea Hydrogenerators
A hydrogenerator turns the flow of water past your hull into clean, silent power, so your batteries stay charged underway without the engine or the noise. Explore the full Watt & Sea range — Cruising and Racing systems, converters, propellers, and genuine parts. Read more ↓
Watt & Sea Hydrogenerators: Clean Power Underway
A hydrogenerator is the simplest way to generate electricity while you sail. As the boat moves, water spins a submerged propeller that drives a brushless alternator — much like a bicycle dynamo — feeding your battery bank through a smart converter. There is no fuel, no exhaust, and almost no sound. For offshore passages and long days at sea, it is often the most dependable source of power on board.
Developed in La Rochelle and proven on the Vendée Globe, Watt & Sea builds two complementary ranges. The Cruising line is the practical choice for bluewater cruisers and shorthanded crews, available in 300 W and 600 W outputs and two leg lengths (610 mm / 24″ and 970 mm / 38″). The Racing line is lighter still, with a controlled-pitch propeller and a transom fixation kit built for the demands of ocean racing.
How it performs
Output rises sharply with boat speed. The first amps arrive at around 2–3 knots; at 5 knots a typical setup produces roughly 120 W (about 10 A at 12 V), climbing toward 500–600 W at offshore passage speeds. Every system ships with a 12/24 V converter using MPPT and step-up technology, auto-detecting your bank and charging lead-acid, AGM, and lithium batteries alike. Pair it with solar for true energy self-sufficiency at anchor and underway.
Choosing and fitting your system
Most owners start with a complete Pack — hydrogenerator, leg, converter, propeller, lifting bracket, and fixation kit — then add propellers matched to their typical speeds, or accessories such as the universal bracket for angled transoms. Installation is best handled by a qualified marine electrician, and every bank should be protected by a 50 A fuse or breaker. Maintenance is minimal: an occasional fresh-water rinse is all the system asks.
MAURIPRO Sailing is a dedicated Watt & Sea source, and our team sails. If you would like help sizing a system to your boat, speed, and power budget, our technical support is here before and after the sale.