iceboat

n. 1. A ship with a reinforced bow to break up ice and keep channels open for navigation; an icebreaker.
Syn. -- icebreaker. [ WordNet 1.5 ]

2. a sailing craft with runners and a cross-shaped frame; suitable for traveling over ice; it is usually propelled by a sail, and sometimes by an engine-powered propeller.
Syn. -- ice yacht. [ WordNet 1.5 ]