Coast Guard inspectors told to take a good look at lithium-ion batteries after Conception dive boat fire

The burned hulk of the Conception is brought to the surface off Santa Cruz Island  on Sept. 12, 2019
The burned hulk of the Conception is brought to the surface off Santa Cruz Island on Sept. 12, 2019.
(Brian van der Brug / Los Angeles Times)

After federal investigators pointed to the charging of lithium-ion batteries as a possible cause of the fire that killed 34 people aboard the Conception dive boat, the U.S. Coast Guard is now directing its inspectors to look more closely at how the batteries are used, charged and stored aboard small vessels.

According to a policy letter issued on Oct. 30, Coast Guard inspectors should look for potentially hazardous conditions such as batteries not being stored in cool, dry places away from combustible material, or batteries being charged using multiple extension cords, also known as daisy chains. Inspectors also should verify that crew members know how to extinguish small lithium-ion battery fires.

The letter follows a notice that the Coast Guard sent to boat owners in the wake of the Conception fire on Labor Day 2019 that warned of the dangers of lithium-ion batteries. And it comes weeks after the National Transportation Safety Board determined that the fire aboard the Conception began in the back of a middle deck salon where lithium-ion batteries were being charged.


The board did not determine whether it was the batteries, the boat’s electrical system or an unattended fire source that ignited the blaze. A member of the crew did recall seeing sparks when plugging in his cell phone before going to bed hours before the fire.

NTSB Chairman Robert Sumwalt said regardless of the source of the fire, those killed probably could have escaped if there had been early detection of the blaze. The board found the owner, Truth Aquatics, failed to have effective oversight of the vessel and did not operate a required roving watch that likely would have detected the fire sooner and could have saved lives. It recommended sweeping changes to small vessel oversight by the Coast Guard, including better smoke detection systems and emergency exits that lead to different areas of the boat.

The Coast Guard, in its new policy, acknowledged that the federal aviation industry had adopted widespread restrictions on lithium-ion batteries long ago. During a hearing last month, several NTSB board members questioned how the Coast Guard had ignored the issue for so long. A Times investigation last year found the Coast Guard had been slow to act on concerns about such batteries on vessels.

During routine inspections of vessels, marine inspectors are now advised to assess the storage, charging and use of such batteries, and to ensure the batteries are stored in a dry and cool location away from combustibles. The charging of batteries should take place in regular occupied spaces with continuous monitoring, such as smoke detectors.

On the Conception, investigators said witnesses reported a spider web of charging, as divers connected all kinds of lithium-ion batteries to a series of power strips. The investigation also revealed that in the year before the fire, a fire had ignited on another vessel in the Truth Aquatics fleet when a lithium-ion battery overheated and had to be tossed overboard.

Ken Kurtis, a respected dive industry expert and owner of Reef Seekers Dive Co., said the new Coast Guard policy failed to address the fact that inspections of the boats are conducted without the passengers who bring the batteries on board. He wonders whether the inspections will make boats any safer.

Marine inspectors are now also required to examine batteries present during their inspections for signs of damage. The new guidance also advises that batteries and chargers for an electronic device be purchased only from the device manufacturer or an authorized reseller. NTSB investigators noted that many of the batteries involved in fires are substandard knock-offs.

Crews are now required to know how to extinguish a lithium-ion battery fire, and vessels must carry dry chemical fire extinguishers or a smothering agent. During the safety briefing, passengers are to be informed of safe charging locations and proper storage of the batteries. The new guidelines for inspectors aren’t designed to address large-scale lithium-ion batteries that are used to power some vessels.