Capt. Taylor Goodman of the Henrico Division of Fire said 12-15 boats were affected. Initial reports of 30 boats were high, Goodman said.
There's no estimate of damage yet, Goodman said, adding that it's "obviously substantial."
The Henrico fire department's fire boat was damaged in the blaze, making it unavailable to fight the fire.
Goodman said they do not yet know what caused the blaze.
About 30 firefighters were part of the response to the blaze. This included Henrico and Chesterfield crews as well as firefighters from Richmond International Airport.
The yacht basin is just west of Interstate 295 on the James River.