http://dictionary.reference.com/search?q=catamaran:
cat·a·ma·ran ( P ) Pronunciation Key (kt-m-rn)
n.
1. A boat with two parallel hulls or floats, especially a light sailboat with a mast mounted on a transverse frame joining the hulls.
2. A raft of logs or floats lashed together and propelled by paddles or sails.

http://www.hobiecat.com/sailing/index.html - Just remember to bring your bikini!