SICILY PORTICELLO, Sicily — Police divers resumed searching Tuesday for six people believed trapped in the hull of a superyacht that sank in deep seas off Sicily, including British tech magnate Mike Lynch, who was celebrating his recent acquittal on fraud charges with the people who defended him at trial. The luxury sailboat, off Porticello near Palermo, was more than 160 feet underwater — far deeper than most recreational divers are certified for and a depth that requires special precautions. Recovery crews could only stay for 12-minute shifts, a measure that slowed efforts to reach the cramped inside of the wreck.

Divers tag-teamed the shifts and used a remote-controlled underwater vehicle to help in the search. The Bayesian, a 184-foot British-flagged yacht, was moored about a half-mile offshore when a storm rolled in before 4 a.m.

Monday. Civil protection officials said they believed the ship was struck by a tornado over the water, known as a waterspout, and sank quickly. Grainy film from closed-circuit cameras from shore, broadcast on the website of the Giornale di Sicilia, showed the tall, illuminated mast of the Bayesian weathering the storm and then disappearing over the course of a minute.

Fifteen of the 22 people aboard survived, including a mother who reported holding her 1-year-old baby over the waves to save her. One body was recovered, identified by officials as the Antiguan-born on-board chef. The rest of the 10-person crew survived, including the captain w.