The LEEN 56 is an innovative power trimaran that builds upon the success of its sailing sisterships, combining advanced construction techniques, cutting-edge propulsion, and spacious design. Like the sailing models from LEEN, the 56 is constructed using vacuum infusion with a mix of fiberglass and Kevlar, making the hull strong yet lightweight. Its trimaran configuration, consisting of a large central hull and two slimmer outer hulls (amas), is not just visually distinct—it’s also key to its performance and efficiency.
At the heart of the LEEN 56’s propulsion system is a 305-horsepower Cummins diesel engine mounted in the central hull, supported by electric pod drives in each of the outer hulls. This hybrid system allows the vessel to operate on electric power alone, achieving speeds of up to 5 knots—ideal for quiet maneuvering in harbors. When full power is engaged, the LEEN 56 can reach speeds up to 20 knots and comfortably cruise between 15 and 18 knots. Remarkably, the boat has an estimated range of 5,000 nautical miles based on testing, and with over 1,300 gallons of fuel on board, transatlantic crossings become a realistic option. At 9 knots, it can travel from France to Boston, and dropping to 8 knots can push the range close to 4,000 miles. With electric drives and generator assist, the boat could eke out up to 4,200 miles at slow speeds.
Optional Hybrid Version:
The optional hybrid version of the LEEN 56 includes a 22 kWh Mastervolt 48V lithium main battery, which serves as a common power reserve for both propulsion and onboard services. For service systems alone, a dedicated 24V Mastervolt gel “buffer” battery pack with a capacity of 200Ah is included. A 17.5 kW generator supports power production for extended range and autonomy.
Charging is handled by a set of 50A 220V/48V Mastervolt Mass chargers, while power conversion is managed by Mastervolt 48V/220V converters. Propulsion is optionally enhanced by two Bellmarine DriveMaster electric motors, which require the generator option to function. These motors deliver a combined power output of 30 kW (2 x 15 kW) with 95 Nm of torque and are directly coupled via shaft line transmission.
The LEEN 56 stands apart in both form and function. The trimaran layout provides significant advantages over traditional monohulls and catamarans, blending the seakeeping and handling characteristics of a monohull with the stability and space of a multihull. Unlike most trimarans which used the amas for storage or tanks, LEEN’s design integrates the amas into usable living space, following in the footsteps of their NEEL sailing trimarans. The result is a vessel with a 340-square-foot flybridge, expansive foredeck, and a large aft cockpit—features rarely seen in traditional trawler designs.
Efficiency is a core part of the LEEN 56’s appeal. With its hybrid system, the vessel boasts extremely low hydrodynamic resistance, thanks to the trimaran hull shape and careful design by architects Nivelt and Frutschi. Compared to twin-diesel monohulls or power catamarans, the LEEN 56 is significantly more fuel-efficient—twice as efficient as a power cat, and potentially ten times more so than a conventional monohull. The electric-only mode enables quiet docking and short harbor maneuvers while the onboard genset keeps the lithium battery bank topped up. At anchor, the batteries can support 24-hour autonomy for all household systems.
Inside, the LEEN 56 offers exceptional livability. Unlike traditional trimarans with cramped interiors, LEEN’s design delivers spacious accommodations and tasteful finishes throughout. With over 2,000 multihulls built in 40 years, LEEN’s builder, has the experience and vision to push the power trimaran concept forward—already planning a larger 72-foot model. The LEEN 56 delivers a unique blend of long-range capability, efficiency, comfort, and space—all in a bold, head-turning package.
At the bow, the glazed wheelhouse features navigation equipment and a cozy saloon with an L-shaped sofa, perfect for relaxing and enjoying the view. A gangway door provides easy deck access for docking and mooring.
The owner’s suite spans two levels on the starboard side, with a bedroom on the upper level featuring an island bed, desk, bookcase, and ample storage. A private staircase leads to the lower-level bathroom, equipped with dual basins, a shower, and a separate toilet.
The standard LEEN 56 layout includes three double cabins, each with its own shower room: the owner’s suite, a forward guest cabin in the central hull, and another in the port-side hull with an en suite. Optional rear cabins can add space for up to 11 passengers.
The light-wood furnishings are crafted by expert cabinetmakers. Exterior layouts for the cockpit and flybridge are customizable. Access to the flybridge is via a cockpit staircase, with a heated wardrobe under the steps for outerwear and dive gear. High bulwarks and covered side decks ensure safe movement on board, reflecting the LEEN 56’s ocean-going capabilities.
