BY JESSE J. HOLLAND

Associated Press

WASHINGTON

--Is it a house or a boat? Does a coffee mug float? The Supreme Court struggled with all types of questions Monday as it tried to figure out what kind of floating structures fall under maritime law, a question that could have a profound impact on popular businesses like floating casinos, hotels and restaurants.

The question was about Fane Lozman's floating home--a gray, two-story vessel approximately 57 feet in length that he towed to the marina in Riviera Beach, one of South Florida's poorest coastal cities.

The city in 2009 told Lozman, a former Chicago financial trader, his right to stay at the marina would be revoked unless he got the structure registered as a vessel and proved it could be moved when a hurricane or tropical storm threatened. The city also demanded payment of more than $3,000 in dockage fees. When Lozman refused to pay or leave the marina, the city used U.S. maritime law to impose a lien on the structure as a vessel. Lozman argued in court that it was a house (it had no engines, no bilge pumps, no steering mechanism, no lights or navigation aids), which would have given it some protection from seizure under state law.