The key headline from the Bayesian interim report is that the yacht took less than 15 seconds to heel irrecoverably.
The UK-based Marine Accident Investigation Branch (MAIB) report is the first official such document to be published into the sinking of the Bayesian which resulted in seven deaths off Sicily, including that of the yacht’s owner Mike Lynch, and his 18-year-old daughter Hannah in August 2024.
As part of the Bayesian interim report, MAIB investigators have pieced together the sequence of events, the movements of the 10 crew and 12 guests onboard, and the rapid timeline of the sudden tragedy.
On 18 August, the Bayesian – a 183ft/56m Perini Navi superyacht launched in 2008 – was anchored at Cefalù, on the northern coast of Sicily, but with the wind increasing, it was decided to motor to Porticello, 25nm to the west, for the night – both for shelter from the forecast weather and to easily disembark guests the following day.
The Bayesian interim report notes: “At 2124 Bayesian anchored to the east of the main breakwater. The centreboard [or swing keel] was in the raised position. Another yacht, the Sir Robert Baden Powell was also at anchor nearby.
“The seas were calm and there was a very light wind from the north-west. Thunderstorms had been forecast, and those on board Bayesian could see occasional flashes of lightning away to the west. Bayesian’s skipper left instructions to be woken by the overnight watchkeepers if the wind speed increased above 20 knots or if there were signs that Bayesian was dragging anchor. Having checked the latest weather forecast, the skipper then went to bed.”
As the last guest went to bed, the first deckhand and evening steward stood an anchor watch. At 0100, a second deckhand took over. The wind was no more than 8kts, and there were no signs of Bayesian dragging anchor.
Approaching storm
At 0300, the second deckhand noted that although the wind was still 8kt from the west, the thunderclouds and lightning seemed to be getting closer. At around 0355, they videoed the advancing storm and posted it on social media, and went on deck to close the forward hatches and cockpit windows to keep the rain out. The wind picked up to 30kts, hitting Bayesian broad on the port bow. The yacht began listing to starboard and the deckhand thought it had started dragging its anchor. The MAIB investigation confirms that, at around 0357, both Bayesian and Sir Robert Baden Powell began dragging their anchors in the rapidly worsening weather.
A few minutes later, around 0400, the deckhand woke skipper James Cutfield. At the same time the chief engineer woke up and headed to the engine control room to prepare the yacht for manoeuvring – firing up three generators, and also starting the steering pumps and hydraulic pumps for the yacht’s controllable pitch propeller. Other crew, including the chief officer, chief steward, chef and stewards had been woken by the yacht’s change of motion – by this time the Bayesian was estimated to be listing between 10°-20° to starboard. The skipper gave orders that the rest of the crew should also be woken up as the anchor was dragging.
The MAIB Bayesian interim report says that: “Bayesian was lying with the wind about 60° off the port bow and moving at 1.8kts south-south-east of its original position. Sir Robert Baden Powell was also dragging its anchor at a similar rate in a similar direction.”
Knocked down in just 15 seconds
The Chief Officer, Chief Engineer and Skipper confirmed that the engines and pumps were started, and that the Bayesian was ready to move.
The Bayesian interim report notes: “As the skipper prepared to manoeuvre Bayesian up into the wind from their position on the flying bridge, the wind suddenly increased to more than 70kts. The awning over the flying bridge ripped from port to starboard.”
“At 0406, Bayesian violently heeled over to 90° to starboard, taking less than 15 seconds to do so. People, furniture, and loose items fell across the deck. The generators shut down immediately and battery-supplied emergency lighting came on.”
In the dark and chaos, the skipper, one of the parents of the baby, owner (Lynch’s wife Angela Bacares), the bosun and a steward were all injured, either by falling or from things falling on them. The second deckhand was thrown into the sea from their position by the helm on the flying bridge. Meanwhile, in their cabin, two guests used drawers that had slid out of furniture as an improvised ladder to climb out, climbing along walls to escape into the saloon area.Two crew, including the first deckhand, also climbed up the walls to get out of the crew mess via a forward staircase. The report notes: “There was no indication of flooding inside Bayesian until water came in over the starboard rails and, within seconds, entered the internal spaces down the stairwells.”
Escape from flooded Bayesian
As water flooded the yacht, the Chief Engineer managed to escape through the port forward wheelhouse door, then helped the first deckhand out before heading aft to launch one of the two EPIRBs on board. The first deckhand lifted two stewards out through an open door, forward and to port in the wheelhouse, onto the upper deck. The three then made their way aft – and, by this point, into the sea.
The report adds: “Separately, the Chief Officer had found the owner and pushed them through the cascading water up to the skipper on the flying bridge.” The Chief Officer and skipper managed to evacuate the baby and one of its parents by the same route.
The bosun and second deckhand climbed down into the wheelhouse and lifted two guests into the flying bridge, assisted by the Chief Officer and skipper. But as the Bayesian rotated to starboard and began sinking, the Chief Steward, bosun and second deckhand then found themselves trapped in an air pocket by a closed door to the port forward wheelhouse. With the assistance of a guest (who had also been injured), on the outside, they were able to open the door and escape.
In one of the most dramatic descriptions, the report notes that the “Chief Officer, who had been swept to the back of the saloon and into another air pocket, dived down to open the sliding doors at the aft end of the saloon and managed to swim clear of the vessel.
“The skipper organised the abandonment from the flying bridge and instructed the guests and crew present there to swim clear of the mast and boom as the vessel was sinking.”
Launching the liferafts
By 0422, the Chief Engineer had launched the EPIRB and was sitting on the hull of the Bayesian, near the rudder. Having heard shouts from the skipper, they jumped into the sea and swam towards the gathering survivors. A deckhand improvised a tourniquet for the guest with a gashed arm, while the baby was placed on a cushion as a flotation device. Some survivors were treading water while others held on to some cushions that had floated free from the yacht.
The skipper and a deckhand swam back to the Bayesian and tried – but failed – to release the port aft liferaft. The Chief Officer then swam back to the yacht, and released the port forward liferaft from the sinking vessel. The crew towed the liferaft to the survivors.
At approximately 0424, the liferaft was inflated and boarded. The Chief Steward told investigators that from the liferaft they saw the bows of Bayesian rise up and then sink below the surface. Their skipper of Sir Robert Baden Powell also reported briefly seeing a dark triangular shape descending into the water, later believing this to be Bayesian’s bow sinking.
After 10 minutes and two attempts, a parachute flare was fired from the liferaft that was seen by the crew of Sir Robert Baden Powell, who dispatched its tender to recover those on the liferaft, before returning to search for other survivors. However, no further survivors were found, and the bodies of six guests and one crew member were subsequently recovered by the local authorities.
New facts may emerge
An MAIB safety investigation is not designed to apportion blame or liability. As there is also a criminal investigation being conducted by the Public Prosecutor’s Office in Sicily, the MAIB investigation has had limited access to the wreck of the Bayesian and other key evidence.
The MAIB notes that the circumstances depicted in its Bayesian interim report may change, if more evidence held by the Italian authorities is released, or following examination of the wreck. However, the MAIB also investigated the design and stability, operation and emergency procedures of the Bayesian, as well as the forecast weather and conditions experienced.
Storm that sank the Bayesian
The MAIB report notes that: “Early Italian weather forecasts ahead of the accident predicted intense and persistent rain, mainly in the form of showers or thunderstorms… [with] storms [being] accompanied by strong wind gusts.
The MAIB investigation commissioned the Met Office to analyse conditions north of Sicily on 19 August 2024. The Met Office study noted that local data suggested a large amount of convective available potential energy (known as the ‘CAPE’ index) in the atmosphere, which combined with wind shear created conditions that were ‘borderline for the development of supercells’.
Supercells are defined by the MAIB as an “isolated mesocyclonic storm that… produce damaging winds and hail and can produce tornados, or tornadic waterspouts. The thunderstorms have associated updrafts and downdrafts. Updraft associated winds can be tornadic in character and can be associated with winds from 56kts to over 175kts. A downdraft is where precipitation and wind “falls” from the storm. Downdraft associated winds can be intense and cause damage when they reach the ground.”
63.4 knots to capsize the Bayesian
The MAIB also commissioned a detailed study of the Bayesian’s stability – analysing the information in the yacht’s Stability Information Book and the angles of vanishing stability for the yacht at three states of ‘load’ – ie how full the tanks were at the time. The study was conducted by the Wolfson Unit in Southampton, and is complex. Follow up expert analysis of the available data will be released.
Yacht vulnerabilities ‘not known to crew’
The Bayesian interim report states that: “The study indicated that if the wind was blowing directly onto Bayesian’s beam and the yacht was in the ‘motoring’ condition, a gusting wind speed in excess of 63.4kts would likely result in the vessel capsizing.” It adds that, in the state of load that the yacht was in at the time “once Bayesian heeled over to an angle greater than 70.6° (the angle of vanishing stability) there was no chance of a return to an even keel.
The report adds: “These vulnerabilities (when in the motoring condition with sails lowered, the centreboard raised and 10% consumables on board) were not identified in the stability information book carried on board. Consequently, these vulnerabilities were also unknown to either the owner or the crew of Bayesian.”