A 35-foot vessel caught fire while undergoing maintenance work in the Hawaii Kai Marina this morning and sank.

Gasoline vapors and a spark are believed to have caused the fire on a boat, owned by Sea Breeze Parasailing, said Capt Terry Seelig, Honolulu Fire Department spokesman.

Workmen set the boat free so the fire, which was reported at 9:13 a.m., would not endanger the dock at the marina. Firefighters brought the boat fire under control by 9:39 a.m.

Damage to the boat, which later sank, was estimated at $60,000.