Catamaran

[Jason Yan]

A kind of raft or float, consisting of two or more logs
or pieces of wood lashed together, and moved by paddles or sail; --
used as a surf boat and for other purposes on the coasts of the East
and West Indies and South America. Modified forms are much used in the
lumber regions of North America, and at life-saving stations.

[Becky]

Catamaran in Skateboarding. A maneuver in that two skaters on two separate boards sit sideways and facing each other, and hold the two ends of their own boards while placing their feet on their partners boards.

[Jason Yan]

a sailing boat that has two parallel hulls (= floating parts) held together by a single deck (= flat surface)

[Sommer]

A yacht or other boat with twin hulls in parallel.