The sinking of the mega-yacht Bayesian last August 19 with the loss of seven lives stunned the yachting world. The yacht is a centerboard design with the tallest sloop-rigged mast ever built. Yet, its builder, Perini Navi, asserts publically that the 184-foot boat was unsinkable.
But sink she did. Early in the morning on Augst 19, the boat was moored half a mile off the Sicilian town of Porticello when it was hit by a violet squall. Winds built to 60 knot which caused the vessel to drag anchor.
As it slewed sideways it was hit on the beam by gusts of over 70 knots that rolled it well over onto its side. Witnesses aboard the nearby yacht Sir Robert Baden Powell reported that the Bayesian was visible one minute and it simply vanished the next.
The yachts was owned by British tech entrepreneur Mike Lynch, who was lost with his daughter in the sinking, so the accident is being investigated by the UDS’s Marine Accident Investigation Branch (MAIB). This week the Branch issued a preliminary report with some startling information.
The Bayesian was not unsinkable, and her builders may have known that for a fact The MAIB found that the yacht was vulnerable to capsize when motoring with sails furls, the centerboard raised and the hold equipped with only 10% of fuel and stores. This is called “loaded arrival condition” or in design terms “light ship.”
These vulnerabilities were not entered into the boat’s stability information book compiled by the designers and builder and were unknown to the owners and the crew. In this configuration, the Bayesian had a limit of positive stability with 60 knots of wind on her beam of only 70 degrees.
A normal sailing craft has a LPS of over 100 and often as high as 120 degrees. With its centerboard down and her tanks full of fuel, the Bayesian’s LPS would have been much higher and the likelihood of capsize much reduced.
In the squall with 70plus knots of wind, the boat rolled over past 70 degrees and had no way to recover. She simply rolled onto her side, flooded very quickly and sank. The MAIB’s investigation continues.
Read more here.
