Lift Ocean: Retrofitting foils

Lift Ocean from Norway is launching a retrofit system that equips motorboats with foils. Foils are wing-like structures mounted beneath the hull that lift the boat out of the water at certain speeds. This significantly reduces water resistance. The company demonstrated the technology on an Uttern 66 DS in the Oslofjord.

How Foiler technology works

The Lift Ocean System consists of several wings mounted beneath the hull. Once a certain speed is reached, these wings generate lift, in a similar way to aeroplane wings in the air. This lifts the hull out of the water, allowing it to glide on the foils. Only the foils themselves remain in contact with the water. According to the manufacturer, energy consumption is reduced by more than 50 per cent, regardless of whether the boat is powered by an electric motor or a combustion engine.

The test run showed that the Uttern 66 DS, fitted with the Foiler system, glided steadily across the water. The system works both on calm waters and in light swell. It is controlled via the boat’s standard steering system; no additional controls are required.

Technical implementation: the Uttern 66 DS as an example

The Uttern 66 DS is a day cruiser approximately six metres in length. For the demonstration, Lift Ocean fitted the foiling system beneath the existing hull. According to the company, the installation does not require any permanent modifications to the boat. The foils are made of carbon fibre and aluminium. The additional weight is around 80 kilograms.

At low speeds, the boat behaves like a conventional motorboat. From around 15 knots, the hull begins to lift. At 20 to 25 knots, the boat is fully planing on the foils. The height above the water is then around 50 centimetres. The system automatically adapts to different loads and speeds.

Energy efficiency and environmental considerations

The main advantage of the foiler system lies in the energy savings it delivers. Thanks to the reduced water resistance, the boat requires significantly less propulsion power. For electric boats, this extends the range accordingly. For boats with internal combustion engines, fuel consumption is reduced. Lift Ocean estimates the saving at 50 to 60 per cent compared with conventional operation.

The reduced wave formation also protects shorelines and other watercraft. In foiler mode, the boat generates hardly any stern waves. Noise levels are also reduced, as the engine and propulsion system are under less strain. The company sees this as a contribution to more environmentally friendly boating.

Areas of application and availability

Lift Ocean initially developed the system for boats between five and eight metres in length. The technology is particularly well suited to day cruisers, bowriders and smaller cabin boats. The company also sees potential applications for workboats and water taxis. The system can be retrofitted to existing boats or integrated as standard.

According to the start-up, it is currently in talks with several boat builders. The first production models featuring an integrated foiling system could be launched in 2027. Lift Ocean offers bespoke solutions for retrofitting. The company has not yet disclosed any prices. The costs will depend on the size and specification of the boat.

Challenges and limitations

The foiling system works best in calm to moderate seas. In high waves or rough seas, the boat must be operated conventionally. The foils can then be retracted hydraulically. Normal operation is also required in shallow waters or harbours, as the foils protrude about one metre below the hull.

Maintenance of the foilers requires regular checks for damage and wear and tear. The edges of the wings, in particular, are vulnerable to collisions with flotsam or shoals. Lift Ocean recommends annual inspections. The company estimates the service life of the foilers to be around ten years under normal use.