Photo: Capsized Seacor Power liftboat on the evening of the accident, with a Coast Guard response boat in the foreground. (Source: US Coast Guard)

Seacor liftboat capsized while lowering legs – preliminary report

An incident in which the Seacor Power liftboat capsized in the Gulf of Mexico in April 2021 happened while the vessel was lowering legs and turning into the winds, according to a preliminary report by a U.S. government safety investigative agency.

The National Transportation Safety Board (NTSB) on Tuesday issued a preliminary report following the incident with the Seacor Power liftboat in the Gulf of Mexico on 13 April 2021 in which six were fatally injured and seven remain missing.

The NTSB is the lead federal agency for the safety investigation. The Coast Guard, vessel owner Seacor Marine, the National Weather Service, and the American Bureau of Shipping have been named parties to the NTSB investigation.

In the report, the agency said that, about l541 local time on 13 April 2021, the US-flagged 175-foot-long liftboat Seacor Power capsized off the coast of Port Fourchon, Louisiana.

At the time of the incident, nineteen personnel were aboard the vessel, including nine crew, two galley staff, and eight offshore workers. Vessels in the area reported heavy rain, winds exceeding 80 knots, and building seas at the time of the accident.

Search and rescue efforts were hampered by 30–40-knot winds and 10–12-foot seas that persisted throughout the evening and into the next day. Six personnel were rescued by the Coast Guard and Good Samaritan vessels, and the bodies of six fatally injured personnel were recovered. Seven remain missing.

As previously reported, after over seven days of search efforts for the missing crew members of the capsized liftboat, the U.S. Coast Guard suspended the search.

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Coast Guard boat and aircrews, local agency crews and good Samaritans searched for a cumulative 175 hours, covering over 9,200 square nautical miles.

Liftboats are three- or four-legged, self-propelled, self-elevating vessels that provide cranes and deck space for servicing offshore facilities such as oil drilling platforms.

After carrying cargo, equipment, and personnel to the worksite, the vessels elevate or “jack up” out of the water to allow crews to carry out work. The Seacor Power was built in 2002 and acquired by Seacor Marine, the vessel operator, in 2012.

Seacor Power liftboat
Pre-accident photo of the Seacor Power liftboat, left, in the lifted configuration alongside an offshore platform. (Source: Seacor Marine)

About 1330 on the accident day, the Seacor Power liftboat departed Port Fourchon bound for “Main Pass Block 138,” an oil and gas lease area in the Gulf of Mexico east of the Mississippi Delta. The voyage was expected to take 18 hours at a vessel speed of about 4 knots.

Prior to getting underway, the equipment to be used by the offshore workers was loaded onto the Seacor Power’s main deck. A weather report emailed to the vessel at 0702 that morning predicted afternoon winds at 9–12 knots from the southeast, with 3-foot seas, the preliminary report said.

About 1530, a rain squall passed over the liftboat as it transited the open waters of the gulf. Visibility dropped and the winds increased significantly, so the crew decided to lower the Seacor Power’s legs to the seafloor to hold the vessel in position until the storm passed.

According to the NTSB report, when the legs began to descend, the crewmember at the helm attempted to turn the vessel into the winds. Before the turn was completed, the Seacor Power heeled to starboard and capsized.

Several personnel were able to escape out onto the exposed port side of the Seacor Power deckhouse. Good Samaritan vessels in the area responded to the stricken vessel’s location, as well as a pre-commissioning Coast Guard cutter.

Coast Guard response boats, a civilian helicopter, and Coast Guard fixed- and rotary-wing aircraft joined in rescue efforts, but high winds and seas that had built to 10–12 feet prevented them from reaching the personnel remaining on the liftboat. Some who had been clinging to the vessel were washed into the water, and six were eventually rescued. One survivor suffered a serious injury.

The Coast Guard declared the accident a major marine casualty on 14 April and the next day the NTSB launched a full team to the area.

While on scene, investigators collected documentation and interviewed survivors, other personnel who had crewed the vessel, owner and charterer representatives, vessel inspectors and surveyors, and search and rescue responders.

The NTSB said that investigators intend to return to the scene when the Seacor Power is salvaged to inspect the vessel and collect further evidence.