The cause of the fire is currently under investigation, and one man was hospitalized in stable condition. His identity is not known.
The fire was reported at around 4:30 p.m. Thursday, after harbor-goers noticed large flames erupting from a docked boat.
According to authorities, while firefighters traveled to the scene concerned residents protected nearby boats from the flames with hoses.
"Kudos to the citizens who protected the nearby boats with hose-lines until we arrived," The OC Fire Authority said on Twitter. "Firefighters did a tremendous job preventing nearby boats from catching fire."