The incident happened Sunday evening in Richardson Bay just off the Sausalito shoreline, according to the Richardson’s Bay Regional Agency (RBRA).
The Southern Marin Fire Protection District and U.S. Coast Guard responded to a distress call from the 35-foot vessel called Folie Douce. The occupant of the boat, identified as Mark Culver, suffered burns and other minor injuries and was rescued before the boat sank, RBRA said.
Culver was hospitalized and his condition was unknown.
RBRA Harbormaster Curtis Havel said he is working with Southern Marin Fire to determine the cause of the explosion.
“We suspect a propane tank leak could’ve led to this incident,” Havel said in press statement. “Mr. Culver is very lucky to have survived.”
Havel said propane leaks are one of a mariner’s greatest fears since it is heavier than air and a leak can pool in the bilge of a vessel. If a spark reaches the pooled-up propane, “it effectively acts as a bomb,” Havel said.
It is the responsibility of the vessel owner to arrange for retrieval and disposal of a sunken vessel, but Havel said it has not been established whether Culver is the vessel’s owner.
Havel said an abatement proceeding needs to be initiated to have the boat removed from the bay floor as soon as possible because the vessel could be leaking fuel, engine oil and other hazardous material. A 2019 vessel census of anchored Richardson Bay boats determined the Folie Douce was inoperable and not part of the RBRA’s Safe and Seaworthy Program.
A transition plan is underway to enforce anchoring time limits, remove marine debris vessels, connect vulnerable individuals on the anchorage with housing alternatives, and protect Richardson Bay’s eelgrass beds.