Lewmar Bow Thrusters – Blue Generation Electric Series (2 kW to 10 kW)

Lewmar’s Blue Generation bow thrusters are the company’s state-of-the-art electric thruster units, engineered to deliver higher performance, quieter operation, and more precise control than ever before. Each model in this series features improved propeller hydrodynamics (many Blue Gen thrusters use 5-blade propellers on single-prop models or counter-rotating twin propellers on the larger models), which increases thrust output while reducing cavitation and underwater noise.

Innovations in Blue Generation: These thrusters are equipped with next-generation electric motors that boast increased efficiency and optimized cooling. Some models (especially the higher power 8 kW and 10 kW units) incorporate thermal protection and active cooling measures – for instance, forced air cooling fans or water-cooled motor housings – allowing longer run times without overheating (a higher duty cycle). The integrated controller (or optional external control unit) enables proportional thrust control, meaning the pilot can adjust thrust output smoothly (not just full ON/OFF) if paired with a suitable proportional control panel.

Model Range Overview:

• Lewmar 2 kW, 12V (Blue Gen) – Model 125TT 2.0: A compact thruster delivering roughly 35 kgf of thrust. Ideal for powerboats and sailing yachts around 6–9 meters in length, this unit greatly eases docking maneuvers. It typically comes with a single propeller (about 125–140 mm diameter) with a 5-blade design for quiet operation. Pairs with a Ø125 or Ø140 mm tunnel. Despite its small size, it packs enough power to control a small vessel’s bow in moderate conditions.
• Lewmar 3 kW, 12V (Blue Gen) – Model 185TT 3.0: A robust thruster for mid-sized vessels (~9–12 m). With approximately 58 kgf of thrust, it provides confident handling even in stiff winds or currents. It features a single 185 mm diameter propeller optimized for maximum thrust. This thruster uses a Ø185 mm tunnel. Notably, installing a thruster of this power in smaller boats should be done carefully to ensure the hull can handle the forces; when properly installed, it offers quick response and strong control authority.
• Lewmar 5 kW, 24V (Blue Gen) – Models 185TT 5.0 or 250TT 5.0: A higher-power thruster designed for yachts in the ~12–15 m range. With around 90–100 kgf of thrust, it makes maneuvering larger, heavier yachts much easier. Depending on the exact variant, the 5 kW thruster may use either counter-rotating twin propellers (for the version that fits a 250 mm tunnel) or a high-efficiency single propeller (for the version fitting a 185 mm tunnel). It operates on a 24V system to keep currents manageable. This thruster strikes a balance between power and size, fitting many cruising yachts and small motor yachts.
• Lewmar 8 kW, 24V (Blue Gen) – Model 250TT 8.0: A powerful thruster aimed at large motor yachts and small commercial craft (~15–20 m length). With dual counter-rotating propellers in a Ø250 mm tunnel, this unit can generate roughly 140–160 kgf of thrust, sufficient to overcome wind and inertia on a substantial vessel. The counter-rotating design cancels out the torque on the boat and maximizes thrust efficiency. The heavy-duty motor is built for frequent use and includes temperature sensors to protect against overheating. This model provides serious maneuvering capability for larger yachts, often allowing docking in challenging conditions with ease.
• Lewmar 10.8 kW, 24V (Blue Gen) – Model 300TT 10.8: The most powerful standard electric thruster from Lewmar, intended for superyachts 20 m and above. Featuring dual Ø300 mm propellers, it delivers over 200 kgf of thrust – an impressive amount for an electric thruster. Such power enables confident bow control on vessels 80 ft or more. The 10 kW thruster usually integrates with advanced proportional control systems and often requires a longer tunnel for optimal performance (to properly channel the water flow). It runs on 24V high-current supply and should be installed with professional oversight, including robust power cabling, dedicated fuse/breaker systems, and appropriate control electronics.

Safety and Control: All Blue Generation thrusters include built-in safety features – both electronic and mechanical. If a motor’s temperature exceeds safe limits, the system will automatically reduce output or temporarily shut down to prevent damage. Likewise, if the supply voltage drops too low (indicating drained batteries), the thruster will signal an alert and inhibit operation under a certain voltage threshold, protecting both the thruster and the electrical system from harmful low-voltage conditions. Lewmar provides a range of control panels (both standard on/off and proportional) compatible with these thrusters – integration is plug-and-play using the provided wiring harnesses and connectors.

• Quiet Operation: Thanks to improved propeller designs and better hydrodynamic flow in the tunnel, Blue Gen thrusters run more quietly than earlier models. This translates to less vibration and noise transmitted into the hull – a significant comfort benefit for those on board, especially for thrusters installed near living quarters or cabins.
• Installation: Each thruster is supplied as a hardware kit, including the thruster unit (motor with gearbox and propeller assembly) and essential mounting hardware. For a complete installation, an appropriately sized tunnel and a control panel are required (sold separately to match the vessel’s needs). The Blue Generation models are compatible with Lewmar tunnels (fiberglass or metal) of the corresponding diameter. Installation should follow Lewmar’s guidelines; proper alignment and sealing are crucial. Larger models may also come with additional wiring or control modules. It is recommended that high-power units (like 8 kW and above) be installed by professionals or experienced installers, as they involve substantial electrical currents and mechanical forces.