Watt&Sea Cruising 300 Hydrogenerator – 300W, Long 970mm Leg (for Boats up to ~35ft, High Transom)

The Watt&Sea Cruising 300 with a 970mm leg is a variant of the popular hydrogenerator, intended for boats where the transom mounting point is higher above the waterline. This “long” version provides the same reliable 300W power output and all the benefits of the standard Cruising 300, but with an extended strut that ensures optimal propeller immersion in deeper water. If your yacht has a high aft deck, a substantial stern rail, or any structure requiring a longer reach to get into clean water behind the transom, this version is the perfect solution.

With its extended 970mm mast, the generator’s propeller stays below the surface even in significant waves or when the yacht heels under sail. This means you don’t lose charging capability when the boat pitches or in rough seas – a key factor during ocean swells or heavy side winds. The mechanical and electrical characteristics of the unit are identical to the 610mm model: it begins charging around ~3 knots, produces about 8 amps at 5–5.5 knots, and follows a rising power curve up to ~300W by ~8–10 knots. Water drag remains minimal thanks to the strut’s hydrodynamic profile and the efficient three-blade propeller.

• Tailored for higher transoms: This model allows hydrogenerator installation on hulls with more freeboard – e.g., sailboats with a high stern, catamarans with a broad aft beam, or boats with existing platforms/passerelles. The long leg overcomes this height, positioning the propeller at the correct depth (20–30cm below the surface) for optimal energy generation.
• No compromise in performance: Despite being longer, the 970mm version is built with the same rigidity and strength. The reinforced aluminum alloy prevents vibration or flexing of the mast even under high water pressure. The prop runs smoothly and efficiently; you can also swap to different prop sizes if needed (standard 240mm, optional 280mm for slower speeds or 200mm for faster speeds) to fine-tune performance, just as with the short version.
• Compatibility & modularity: All Watt&Sea Cruising 300 accessories and consumables are compatible with both the long and short versions. This includes the various propellers (240mm standard, 280mm optional for low-speed, or 200mm for high-speed optimization), mounting kits, and spare parts. If you ever switch from one variant to the other (e.g., change boats), you could replace just the aluminum leg (610mm vs 970mm), as the generator head and electronics remain the same.
• Same intelligent electronics: The Cruising 300 (970mm) uses the identical converter with automatic 12/24V switching and Bluetooth monitoring. That means you get the full suite of features – safe multi-stage charging, smartphone monitoring capability, and solar panel integration – regardless of the generator’s length. The built-in electronics ensure the output to your batteries is optimized and will taper off when they’re fully charged, protecting your battery bank.
• Maintenance & warranty: Like the short version, the 970mm hydrogenerator has minimal maintenance requirements. It’s recommended to rinse it with fresh water after long exposure to salt, periodically check the propeller and bearings, and do a full service every 2 years. Watt&Sea provides a 2-year warranty covering manufacturing defects – a testament to their confidence in this product’s quality. With proper use, you can count on tens of thousands of miles of clean energy generation.