A 40-foot motor yacht sustained extensive damage after catching fire at the Queen City Yacht Club dock in Eagle Harbor early Thursday morning.

The Bayliner “Sea’s the Moment” will likely be a total loss, though the vessel was left afloat after responders extinguished the flames, Bainbridge Police Deputy Chief Mark Duncan said.

No one was on board the vessel and there were no injuries. The boat was registered to Chris A. Benson of Des Moines, Wash., who arrived by ferry to survey the damage Thursday morning.

City Harbormaster Tami Allen said the yacht will be towed to a yard off-island to be hauled out.

Fire investigators determined the blaze was likely ignited by a bath mat left too close to an electric cabin heater.

Duncan said it’s not unusual for boat fires to be traced back heaters or other electrical appliances left on board.

“Unfortunately these kinds of boat fires aren’t that uncommon,” he said.

The crackling of flames awoke Barbara and Eric Wood aboard their boat BarbEric, moored near Sea’s the Moment, at 3 a.m. Thursday.

Barbara Wood ran to a payphone on shore to call 911. Returning to the dock she was surprised to see that another vessel had arrived out of the darkness and was already spraying water on the flames.

The responding vessel was the tugboat Shelley Foss, which was motoring into the harbor for a job at the ferry maintenance yard that morning.

Captain Joel Russell said he and his crew noticed an orange glow from the direction of the downtown marinas and rounded the bend to to investigate.

When the Shelley Foss arrived on scene, Sea’s the Moment was already “ablaze from stem to stern,” he said. The tug’s crew used a fire pump and a 1,000-gallon-per-minute fire monitor to beat back the flames until firefighters and police arrived.

“It’s company policy and our policy on board to help out whenever we can,” Russell said. “You never know when it’s going to be us.”

Twenty responding Bainbridge firefighters used the fireboat and ran hoses run from shore to extinguish the blaze before it could spread to the dock and nearby boats.

“Any time you have a boat fire it’s pretty similar to an RV fire,” Bainbridge Fire Marshal Jared Moravec said. “They tend to burn pretty hot and pretty fast. We’re just fortunate that the tug was in the area and able to keep the fire in check until we got there.”

A marine spill response trailer, paid for by the state’s Department of Ecology and stored by the fire department at its Phelps Road station, was towed to the waterfront. A floating boom was unfolded and positioned around the burning boat to contain any fuel or other contaminants.

It turned out to be a precaution, because the fire did not rupture any tanks and the vessel didn’t sink, Allen said.

“There were no spills off the boat, so we missed that bullet,” she said.