The Seawing is a towed hydrogenerator with two counter-rotating propellers. The system is connected to the boat via a line. The cable required for power transmission is housed inside the cordage and is therefore protected from mechanical damage. The buoyancy body in combination with the solid stainless steel fin is designed to ensure stable towing below the surface.
Robust construction
The Seawing consists of a frame made of seawater-resistant aluminium, to which two counter-rotating propellers, a float and a stainless steel fin are attached. Sacrificial anodes are fitted to the propellers and the fin to prevent corrosion problems. The total weight of the trolling generator is around six kilograms and the propellers have a diameter of 240 mm. This propeller size is suitable for slow boats with an average speed of between five and six knots. For faster yachts, the manufacturer recommends using the 210 mm high-speed propellers.
The power of the Seawing is limited by the software to a maximum power of 600 watts. When this maximum is reached, the trolling generator automatically reduces its output. The motors are fully encapsulated with polyurethane resin and silicone (winding and magnets). An additional ceramic bearing at the rear of the motor counteracts the pull of the propellers.
Simple installation
The line of the towing generator is attached to the boat with a stainless steel carabiner. To ensure that the generator reaches the optimum working depth, the attachment point should be a maximum of one metre above the waterline. The control unit of the Seawing consists of two independent motor controls. The manufacturer promises an electrical efficiency of over 95 per cent, which should ensure low waste heat. The software automatically recognises whether a 12 or 24 volt on-board power supply is available and adjusts its settings accordingly. The quiescent current of the electronics box when switched off is around 600 microamperes, which ensures that the battery remains charged even after months of non-use. The traction generator is monitored using a smartphone app and adjusted to the battery chemistry on board. Lead-acid, Li-ion and LiFePO4 batteries are available. The cable length between the electronics box and batteries can also be configured to compensate for the inevitable voltage drop and achieve the correct end-of-charge voltage. The system can be installed directly at the Manufacturer and costs around 2000 euros.
Technical data:
- Weight: approx. 6 kg
- Propeller diameter: 240 mm (standard), 210 mm (high speed)
- Frame: Aluminium
- Corrosion protection: sacrificial anodes on propellers and fins
- Take-off speed: 3 knots
- Maximum power: 600 watts (software-limited)
- Electrical conversion efficiency: over 95%
- Automatic voltage detection: 12V or 24V
- Battery chemistry settings: Lead-acid, Li-Ion, LiFePO4
