Issuma is a 21 ton, 15m (53 foot) steel staysail schooner with all the ballast--4.5 tons--in the centerboard.

The boat was built in 1981 by the META yard in France, to Michel Joubert and Bernard Nivelt's Damien II design. The design was intended for Antarctic cruising. The idea of the centerboard  was both to be able to retract it inside the hull so ice could not grab it, and to be able to reduce the draft enough to motor into shallow waters to escape ice (which grounds in shallow water). The centerboard trunk comes up to the deck, and when the centerboard is completely raised, part of it is above deck.  I believe Issuma is the 25th vessel built to that design, which is well-known in France.

The boat was sold for owner completion. The first owner unfortunately died before completing the boat, the second owner removed the trunk cabin and put in a well-cambered flush deck for strength, completed the boat, then sailed her 48,000 miles. I am the third owner, and have sailed her over 50,000 miles so far, incluiding a circumnavigation of the Americas.

Length: 15m (53 feet)
Beam: 4.4m (14.4 feet)
Draft, keel up: 1.3m (3.5 feet)
Draft, keel down: 3.1m (10.5 feet)
Displacement: 21 tons
Construction: overlapped, welded, steel plate over transverse frames. Aluminum masts.
Engine: 72HP John Deere 4239, hydraulic drive, twin propellers
Sail Area: