The 35-foot fiber glass motor boat left Loch Lomond Marina in San Rafael at 11:30 a.m.
There were three adults and five children on board. About an hour into the trip when the boat was south of the Richmond-San Rafael Bridge and a half mile off Tiburon, the owner started seeing smoke coming from the vents.
The owner called the Coast Guard and was instructed to put life jackets on everyone, get into the water and wait for help. The owner also fired flares into the air, so other boaters would know they were in trouble.
"He shot two up in the air and didn't get anybody's attention. The third shot he fired across the bow of a boat he saw going by, that got that boats attention and they came over and plucked them out of the water," Capt. Sloan Valentino said.
The eight people were only in the water for five minutes before a nearby pleasure craft arrived on the scene to pull them out of the water. Everyone was checked out by medics and deemed OK.
The Tiburon Fire Department arrived at the scene with one of their boats and put out the fire. They never boarded the motor boat because it was too dangerous. Firefighters heard two explosions which could've been the gas tanks exploding.
The people on board the boat were taken back to Loch Lomond Marina, the location where their boat was pulled to.
A barge was expected to arrive and pull the boat out of the water. Officials will have to place air bags underneath the boat and flip it over in order to get it out.