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It’s hard to read the interim Marine Accident Investigation Branch (MAIB) report into the sinking of the 56-metre sailing yacht Bayesian in August last year and determine that anyone did anything terribly wrong. For the first time we have a narrative of what happened that evening, and what comes through overwhelmingly is a group of human beings doing their best to survive and save lives in an impossible situation. The yacht started dragging its anchor at 3.57am on 19 August and just nine minutes later it was knocked down, leading to irretrievable downflooding. What will come under intense scrutiny is the yacht’s stability booklet, which provided no information on the angle of vanishing stability (AVS) for the yacht with its centreboard in the raised, or “motoring”, position. 

The MAIB has determined that with the centreboard raised, as it was that evening, the real AVS of the yacht was 70.6 degrees – but no one on board knew it. The MAIB also tasked the UK’s Met Office with studying the atmospheric conditions that night, which revealed that “tornadic waterspouts and downdrafts were possible where local winds could reach extreme hurricane force well in excess of 64 knots”. Yet no forecast had predicted such dramatic conditions. Plenty has been written about Bayesian’s 72-metre mast, and there is now no doubt that it contributed to the yacht’s vulnerability. The massive spar “accounted for 50 per cent of the total wind heeling moment of the vessel when the wind was exactly on the beam”, according to the MAIB’s report. Investigators further reported that a gust of 63.4 knots directly on the beam was sufficient to knock the boat down, given the windage of the mast. So as it was, with a real AVS of 70.6 degrees and winds gusting beyond 64 knots, Bayesian stood no chance that night, and everyone on board was oblivious to the danger. With Bayesian now off the seabed the various investigations will continue, but it’s hard to see how the final report will determine anything other than the fact that a series of tragic events led to the sinking and the deaths of seven people, rather than the actions of a small number of crew.

Stewart Campbell
Global editor-in-chief

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