Bayesian superyacht sinking latest: Diver speaks of ‘unbearable’ tension in search for Mike Lynch’s daughter Hannah

Hatches and doors left open overnight on the superyacht Bayesian may have caused it to sink in Italy, a sailing expert has said.

Sam Jefferson, editor of magazine Sailing Today, believes the vessel’s huge mast – the tallest in the world, at 72 metres – is also likely to have contributed to the deadly event.

Mr Jefferson told the PA news agency: “I would have said that the boat got hit very hard by the wind, it was pinned over on its side.

“I imagine all the doors were open because it was hot, so there were enough hatches and doors open that it filled with water very quickly and sank like that.

“The reason it got pinned over so hard was because the mast is huge. It acted almost like a sail. [It] pushed the boat hard over on its side.

“[The boat] filled with water before it could right. This is all speculation, but that’s the only logical explanation.”

A diver who led the search for Mike Lynch and his guests onboard the yacht Bayesian said that his 18-year-old daughter Hannah was the hardest to find, as he recalled the “unbearable” tension facing his team.

“The yacht was on its right hand side. All of the cabins had been invaded with floating debris, mattresses, sheets, wardrobes,” he told MailOnline.

“It was due to this large amount of floating debris that the operation progressed with difficulty.

“The cabins were dark and there was barely any visibility, so as a result the environment was hostile and the situation was getting more difficult.

“She [Hannah] was the furthest away, we are talking about a situation where to advance just a metre took four or five dives.

“It was such a relief to have found her after almost five days. The tension had been unbearable until then.”

Charities dedicated to rescuing asylum-seekers in the Mediterranean have hit out at the “double standard” highlighted by the media coverage and resources given to the Bayesian search effort.

“For us, every death in the Mediterranean is one too many, no matter where they come from or how much money they make,” the organisation Sea-Eye, who recently rescued 262 people in the Mediterranean, said in a statement to The Guardian.

They added: “Sadly, it makes a difference in the media, in our society and in politics, who is drowning. We have noticed that the coverage of the situation in the Mediterranean, of tragedies or of our rescues in recent months has not been nearly as extensive as in the case of the Sicilian shipwreck in recent days.”

Days after the Bayesian sank, distress calls relating to a dinghy carrying 43 people in the Mediterranean were ignored and the vessel was left in peril for more than 24 hours until the charity Sea-Watch got there “just in time” to rescue those onboard and in the surrounding waters, the organisation alleged.

“For the Italian and European authorities, there are Shipwrecks and then there are shipwrecks, one capitalised and the other lowercase, one immediately rescued and the other abandoned to its fate,” Sea-Watch said, adding: “There was no rescue effort by the authorities. That’s no coincidence; it’s the EU’s double standard.”

The Bayesian was built in 2008 by Perini Navi, an Italian luxury yacht maker. It featured the world’s tallest aluminium mast, measuring 72 metres (236 feet).

Giovanni Costantino, chief executive of the Italian Sea Group – which owns Perini – said the yacht was “one of the safest boats in the world” and basically unsinkable.

The captain of a nearby boat has recalled that, when the winds surged, he had turned on the engine to keep control of his vessel and avoid a collision with the Bayesian, which had been anchored alongside him.

“We managed to keep the ship in position and after the storm was over, we noticed that the ship behind us was gone,” Karsten Borner said.

The other boat “went flat on the water, and then down,” he added. He said his crew then found some of the survivors on a life raft and took them on board before the coast guard picked them up.

The lawyer for two Bayesian crew members under investigation has said that, similarly to the ship’s captain, his clients were under investigation on charges of manslaughter and causing a shipwreck – which does not imply guilt and will not necessarily lead to charges.

Lawyer Marco Scopesi told the New York Times that his clients were under investigation “in a very general way”, adding: “The prosecution hasn’t focused on anything specifically.”

“We’re still at the beginning” of the investigation, he told the outlet.

The swift descent of the Bayesian underwater has puzzled seafarers and nautical engineers, who say the vessel should have taken hours to fill up with enough water to sink it.

There have been suggestions that one or more portholes, windows or other openings may have been left open, or were broken or smashed by the storm, letting in water.

The yacht was capable of tilting to around 75-90 degrees, depending on whether its keel was up or down, and still revert to upright position, former captain Stephen Edwards wrote on his Linkedin profile.

He said the “Downflooding Angle”, at which water could start entering the vessel via the engine room or ventilation ducts, was 40-45 degrees, and once surpassed, would have put the yacht “in serious trouble”.

Experts have questioned if the yacht had been moored with its keel up, potentially compromising its stability, but Edwards said that under the boat’s operating rules, the keel was not required to be down while at anchor.

The keel is a fin-like stabilising structure under the hull, which can be lifted to reduce the depth of the boat in shallow waters or harbours. In the Bayesian, it could reduce the yacht’s below-water surface from around 10 to 4 metres.

The captain of Mike Lynch’s yacht flew out of Palermo on Thursday, 10 days after the British tech tycoon and six other people were killed when the vessel sank off the coast of Sicily.

James Cutfield left the Sicilian capital on a private jet, an investigative source said, adding the destination of the flight was unknown. Cutfield, a New Zealander, lives with his wife in Palma on the Spanish island of Mallorca.

Cutfield was put under investigation for manslaughter and shipwreck earlier this week and declined to answer questions from prosecutors on Tuesday.

Two other crew members were placed under investigation on Wednesday. Being investigated does not imply guilt and does not mean formal charges will follow.

Those facing investigation have no obligation to stay in Italy but have to nominate lawyers so that the authorities have a way of remaining in contact with them.