The report into the sinking of the 60-metre superyacht Yogi last February by the investigation team of the French BEAmer organisation has found a number of possible factors contibuting to the loss of the yacht, though it expressed uncertainty as to the reasons for the “progressive flooding of the three compartments in the aft zone”, which caused the stability of the yacht to deteriorate and eventually to founder in 500 metres of water.

The yacht was on passage to Cannes across the Aegean Sea at night in a following sea in good weather, making 14 knots. At 0146 the starboard engine was shut down after a fresh-water alarm went off, and at 0200 the port engine shut down automatically after an overheat. After checks, the port engine was restarted and the captain decided to head for Skyros, an island 25 miles away. But the helm “was out of order and a rudder angle of 30 degrees to startboard was displayed”. On investigating the yacht’s two beach clubs and steering room aft, the crew found that they were flooding, and though pumping was started the flooding got worse. The crew were finally lifted to safety by the Greek air force by 0850.

The investigators suggest a tightness failure of one of the stern door seal is a possible reason for the ingress, although they reject the notion that it was a failure of one of the rudder trunks. They also say a high-water alarm in the steering room should have gone off to alert the crew of a problem with water ingress, and they note a failure of the draining system in the aft compartments. The crew, they say, had managed the crisis “without unnecessary risk-taking and with cold blood under the master’s authority”.

Among the reports recommendations are that owners should inform the yacht’s classification society of any modifications that could question the validity of the original certificates. They also recommend that naval architects and yacht builders “free themselves from the standards of aesthetic that could impair the safety of the crew and passengers” and “to ban architectural options that pose risks for vessel safety”.