Some witnesses reported hearing what sounded like an explosion either just before or near the start of the fire, which was reported just after 9 p.m. near the 14000 block of Marquesas Way.
One boat was fully engulfed in flames. It appeared a second adjacent boat was also damaged.
A boat docked in Marina del Rey was heavily damaged by a fire Thursday night.
Los Angeles County firefighters got the flames under control and no injuries were immediately reported.
The cause of the fire remains under investigation.