For just over $500,000, the Lagoon 440, built by Lagoon America (Annapolis, MD) offers three cabins, standard diesel engines (electric propulsion system optional), sails, and delivery (but not rigging, launching, or taxes) to East Coast USA.  Who’s in?

Most notable of the Lagoon 440 is its propulsion system, a diesel-electric hybrid. Twin electric motors, one mounted in each hull, power the boat and turn the props at 900 - 1,100 rpm at cruise, an ideal speed for efficiency in this size range.

Energy for the motors comes from a 22-kW diesel genset, which charges a massive storage bank equivalent to twelve 8D-size batteries. (The extra weight of the batteries is compensated for by the lack of two heavy diesel engines mounted near the sterns and by the ability to mount the battery weight closer to the center of the boat.) The batteries are wired in series to give 144 volts, and the genset starts automatically when the batteries need recharging; this happens at 50 – 80% discharge and is adjustable.

It also has the equivalent of regenerative braking or coasting in a hybrid car. In a hybrid car, braking or coasting downhill puts the motor into generator mode, recharging the batteries.  In the Lagoon 440, sailing in a good breeze makes the props turn the drive shaft as they move through the water, cranking the motors and generating electric current from them. This recharges the battery bank.

It also works well on open-ocean passages, and not so well in light winds. In strong winds, so much current is generated that the control system shut off the motors and stopped the props to prevent overcharging the batteries.

As for the construction, the hulls (solid fiberglass below the waterline) and decks are hand laid and then vacuum-bagged to ensure light weight and complete resin infusion. Closed-cell foam core is used above the waterline to minimize weight and provide extra stiffness. The deck is cored with balsa, and areas where deck hardware attaches are reinforced with solid glass.  The rig is aluminum.  The Lagoon 440 is nearly silent under power, and it offers better weight distribution and better fuel economy.