The offshore drilling platform lost stability during preparations for a new campaign, prompting a major search operation and environmental monitoring.
LIBREVILLE, GABON — An offshore drilling rig sank off southern Gabon after losing stability during preparations for a drilling campaign, leaving one worker reported dead and four others missing as authorities continued search-and-rescue operations and monitored the area for possible pollution.
The Prospector 5, a jack-up rig owned and operated by Borr Drilling, went down off the coast near Mayumba on Oct. 24. The company said 115 people were aboard when the incident occurred and 110 were safely accounted for. Borr Drilling initially said five people remained unaccounted for, while subsequent reporting citing Gabonese officials said one of those workers had died and four remained missing. The company had not immediately reflected that death in its own published personnel count.
The accident occurred at about 8:37 p.m. local time while the rig was conducting jacking operations in preparation for work on the Dussafu Marine license, according to BW Energy, which had contracted the rig. Preliminary information from Borr Drilling indicated that the rig experienced a “punch through” during preload activities, causing it to lose stability and sink. A punch-through can occur when one of a jack-up rig’s supporting legs unexpectedly penetrates weaker seabed material.
The rig had not yet begun its planned drilling campaign. BW Energy said production at its nearby MaBoMo facility was shut down under standard procedures connected with the drilling preparations. The company said there had been no reported damage to the production facility or related equipment and no reported accidental discharge of harmful substances into the sea from the facility.
Those statements offered some reassurance as attention also turned to the environmental risks created by a large offshore structure sinking near Gabon’s coast. Authorities deployed pollution-response resources while the search continued. No major oil spill had been confirmed from the accident, and the amount and type of fuel or other material remaining aboard the sunken rig had not been publicly established in the information available Tuesday.
The sinking occurred in waters off Mayumba in southern Gabon, near a coastline known for sensitive marine and coastal habitat. The government activated a crisis response involving maritime authorities and the oil sector and ordered an investigation into the accident. Search operations were expanded as crews tried to locate the missing workers, with marine and aerial assets taking part.
Gabonese officials said three of the missing workers were Gabonese nationals. Reuters reported that the worker who died was an Indian national, citing people familiar with the incident, while Gabonese authorities continued to provide updates as the rescue effort developed. With casualty information changing after the sinking, official and company accounts have not always used the same tally.
Borr Drilling Chief Executive Bruno Morand said the company’s immediate priority was supporting search operations and the welfare of everyone affected. The company said it was working with Gabonese authorities, BW Energy and emergency specialists while maintaining contact with families of the missing workers.
The loss of the Prospector 5 also creates uncertainty for BW Energy’s planned drilling program. The rig had been contracted for a campaign expected to support new offshore production, and its sinking removes it from service while investigators work to determine precisely why it became unstable. Borr Drilling said a full investigation would be carried out with its partners and authorities.
As of Tuesday, search operations for the remaining missing personnel were continuing and authorities had not announced evidence of a major offshore pollution event. Environmental teams remained part of the response, while investigators faced separate questions about the seabed failure, the rig’s loss of stability and the sequence that led to its sinking.
Author note: Last updated October 27, 2026.