Sleipner SX35 12 Volt External Stern Thruster

Sleipner SX35 12 Volt External Stern Thruster

The Sleipner SX35 12 Volt External Stern Thruster will help Improve your boat's berthing and manoeuvrability with the powerful Sleipner SX35 12 Volt External Stern Thruster. This easy-to-install thruster is less intrusive than traditional tunnel style thrusters, requiring only a 50mm hole. Take advantage of its advanced technology and enjoy a smoother and more efficient sailing experience. It is the world’s most compact external thruster, and can be fitted in any hull shape or material.

Sleipner SX35 12 Volt External Stern Thruster Key Features

• Suitable for boats up to 32 feet with a hull thickness of up to 150mm.

• Easy to install

• No fibreglass work

• Energy efficient

• Long running time

• Fits many hull shapes

Morgan Marine can provide fitting if required, please contact us for pricing. 

Sleipner SX35 12 Volt External Stern Thruster FAQs

• What size boat is the SX35 suitable for? It is designed for vessels between 19 and 32 feet (6–10 meters).

• Can it be used as a bow thruster? Yes. While primarily a stern thruster, it can be installed as a bow thruster if used with a specialized hydrodynamic "Hydropod" mounting kit.

• What is the maximum hull thickness for installation? The standard unit fits transoms up to 50mm (2 inches), but an extended version is available for hulls up to 150mm. 

• How much thrust does it provide? It delivers 35kg (77 lbs) of thrust at 10.5V and up to 43kg (94 lbs) at 12V.

• How long can I run it continuously? It has a typical S2 duty cycle of 2–3 minutes at 20°C ambient temperature. External placement allows for more efficient water cooling compared to internal tunnel thrusters.

• Is it loud? The SX35 is designed for minimal noise using a 5-bladed Q-prop™ and vibration-absorbing sleeves on hull connections. 

• Does it require extensive fiberglass (GRP) work? No. It is an external unit requiring only three small holes to be drilled through the transom for mounting and cables.

• Can it be installed on boats with twin stern drives? Yes. Optional cowls can be added to divert water flow past stern drive legs that would otherwise block the thrust.

• What is the minimum mounting depth? The center of the tunnel should be at least 140mm (5.5 inches) below the waterline to prevent air suction and maintain efficiency. 

• Can I use Lithium (Li-ion) batteries? Standard "on/off" DC models like the SX35 can be damaged by the higher sustained voltage of Lithium batteries, leading to overheating or cavitation. Sleipner recommends Lead-acid, AGM, or Gel batteries for this model.

• Is it safe for gasoline/petrol boats? Yes, the unit is ignition protected (ISO 8846 and UL 1500 certified) with a hermetically sealed housing, making it safe for installation near fuel sources.

• Does it have a proportional speed control option? The standard SX35 is an on/off unit, but a PRO™ version (SXP35) is available for variable speed control and longer run times

• What maintenance does it require? Owners should replace the anode before every season (or when half-eroded), check the propeller and tunnel for marine growth, and apply antifouling paint to the gear leg and propeller.

• Is the drive leg lubricated? The gear leg is pre-filled and sealed for lifetime lubrication using mechanical ceramic/carbon seals.