The person who was aboard the 40-foot vessel was taken off without injuries, according to the Bainbridge Island Fire Department.
Witnesses noticed smoke coming from the vessel at about 3:30 p.m. as it was getting underway near the mouth of Eagle Harbor. Crews had the flames under control by 5 p.m.
The fire's cause is unknown, according to Assistant Fire Chief Luke Carpenter.
Bainbridge Fire was assisted by Coast Guard and Seattle Fire Department crews.