The U.S. Coast Guard suspended an 18-hour search Wednesday for a Woodland Hills resident and another person who may have been aboard a pleasure boat found burning off the coast of Marina del Rey.

Sheriff's arson investigators were working to determine the cause of the Tuesday evening fire aboard the Casey Lynn, a 27-foot recreational cruiser registered to Michael Martinez, a 53-year-old real estate agent from Woodland Hills.

"Right now, all we have is a burned boat," said Los Angeles Sheriff's Department spokesman Steve Whitmore. "Our job is to determine the origin of the fire."

Authorities say they likely will refer the case to homicide detectives.

At Coldwell Banker in Calabasas, where Martinez has worked as a real estate agent for nine years, colleagues hoped to hear good news about the search.

"They are hoping he is found safe and sound," company spokeswoman Leeza Hoyt said. "He was very well respected."

The Casey Lynn, a white Sea Ray with limited space below deck, was seen sailing Tuesday out of Marina del Ray, where it may have been berthed. About 5 p.m., the Coast Guard received calls that a boat was on fire about a mile offshore and that two people may be aboard, said Lt. J.G. Taylor Stutin.

County firefighters and lifeguards responded on boats and doused the flames, but could not locate any survivors. A Coast Guard helicopter and patrol boat joined in the search of the 60-degree waters, but suspended

"We've exhausted the drift models," said Stutin, assigned to the the Coast Guard Command Center in San Pedro. "We also have survivability models - we can calculate how long people can survive in these conditions.

"That factored into our decision to suspend the search."