Bayesian was sunk by ‘extreme winds’, interim report says
Bayesian before the incident. Image courtesy Karsten Borner, skipper of Sir Robert Baden Powell.
A new interim report by the UK’s Marine Accident Investigation Branch (MAIB), released Thursday (15 May 2025), has detailed the final moments of British tech tycoon Mike Lynch’s superyacht Bayesian, which killed Lynch and six others when it sank off Sicily in August 2024.
The report concludes that wind speeds of 63.4 knots (117km/h) on the yacht’s beam were sufficient to tip over Bayesian, and that the yacht could not recover once it had heeled beyond 70 degrees.
The news comes after another tragedy, in which a Dutch diver working on preliminary operations to raise Bayesian, died during underwater salvage work on Friday (9 May 2025). Local media have reported that the specialist diver was killed by an explosion caused by an underwater oxy-hydrogen cutting torch.
The British-flagged vessel, built by Perini Navi in 2008 and once described by its builders as “basically unsinkable,” was anchored near Porticello on the night of 18 August 2024. It had been moved there earlier in the day to shelter from forecast thunderstorms. By 3am, wind speeds remained low – around 8 knots – but crew reported signs of worsening conditions, including lightning and rising winds.
“The interim report presents a desktop study of the facts as we know them,” says Andrew Moll, chief inspector of marine accidents. “The study has reviewed the yacht’s stability, the likely local weather conditions at the time and the effect of that weather on the yacht. The findings indicate that the extreme wind experienced by Bayesian was sufficient to knock the yacht over. Further, once the yacht had heeled beyond an angle of 70 degrees, the situation was irrecoverable.”
The report details how, at 4:06am local time on 19 August, a violent gust hit the vessel. The Bayesian capsized violently, tipping to a 90-degree angle in under 15 seconds, according to the report. Water surged over the starboard rails and quickly entered through stairwells, flooding interior compartments. The yacht sank in approximately 18 minutes, settling in 50-metre-deep waters.
Reuters reports that when the yacht’s retractable keel was raised, wind speeds in excess of 117 km per hour on the beam were sufficient to knock it over.
Crucially, the MAIB said, this vulnerability was not documented in the Bayesian’s on-board stability information, meaning neither the owner nor the crew knew the danger they were in.
“Wind speeds in excess of 63.4 knots on the beam were sufficient to knock Bayesian over,” the MAIB stated, adding that the yacht became unrecoverable once it heeled beyond 70.6 degrees – the angle of vanishing stability. Investigators also found that the vessel’s towering 72-metre mast – once the tallest on any sailing yacht in the world – acted like an aerofoil, generating significant lateral force and compounding the instability.
In all, seven people died in the disaster: Mike Lynch, 59; his daughter Hannah Lynch, 18; US lawyer Chris Morvillo and his wife Neda; Morgan Stanley International chair Jonathan Bloomer and his wife Judy; and Canadian-Antiguan chef Recaldo Thomas. Fifteen others, including Lynch’s wife Angela Bacares, survived. Many had gathered on the yacht to celebrate Lynch’s acquittal on 15 counts of fraud in a US federal court just weeks earlier.
The MAIB report detailed desperate escape efforts in the moments after the capsize. Some passengers used drawers as improvised ladders. One crew member was thrown into the sea. Others were trapped in air pockets and had to be pulled out by injured guests. The captain ultimately gave the order to abandon ship, and survivors later made it onto a life raft and were rescued by another yacht, Sir Robert Baden Powell.
The Bayesian remains on the seabed, but a salvage operation is underway. It was paused last week after the death of the Dutch diver, but is scheduled to resume today (15 May 2025). Once recovered, the wreck will undergo further examination.
The MAIB cautioned that its findings are provisional. “The circumstances described in the report may change following the release of evidence held by the Italian authorities or following examination of the wreck,” the agency said. Italian prosecutors have opened a criminal investigation into suspected manslaughter, and the yacht’s captain and two crew members are reportedly under investigation.
The Italian Sea Group (TISG), owner of the shipyard that built Bayesian, had previously claimed the vessel was capable of righting itself even with the keel raised and questioned whether the crew had left hatches open. The company, which announced legal proceedings against the New York Times last year in response to an article about the incident, declined to comment to global media on the MAIB’s interim report.
TISG acquired Perini Navi in January 2021 from a bankruptcy auction along with Perini Navi’s brand, archives and real estate.
Inquests into the deaths of the British victims are underway in the UK.
The MAIB’s final report is expected later this year and will include further details such as escape routes and survivability factors.
“The results will be refined as the investigation proceeds, and more information becomes available,” says Moll.
