I read the NY Times article, where the DM got their information. The NY Times consulted with more than a dozen naval architects, engineers and other experts.
It is a good and very long article.
Some of their points are: (paraphrased in case of a paywall, but a free account allows you to read it)
- Two tall doors on either side of the deck, increasing the chances taking on dangerous amounts of water if the boat was pushed over towards its side by high winds
- How close air vents are to the waterline
- Where the ship's ballast was place in the hull ... instead of it being spread evenly through the hull, it was stacked towards the rear of the hull (naval architect says that makes no sense, and he had never seen the main ballast used in this way before)
- The mast is 40 feet taller than the original foremast, and very heavy ... made from at least 24 tons of aluminium as opposed to lighter carbon fibre
- The single mast was not placed where it should have been, because that would have meant it would have gone right through the wheelhouse
- The sunken deck was added (along with the two tall doors), no other Perini yacht in that series have this feature. The deck reduced the boat's buoyancy and allowed the boat to take on huge amounts of water when tipped. The tall doors would allow water to gush down the main staircase.
- The yacht sits lower in the water than other yachts in the same series, making it easier for water to enter through vents and other openings
In addition, the NY Times obtained the stability book for the Bayesian and the stability book for a sister ship. The Bayesian was less stable, a two masted ship could lean 10 degrees farther on its side before taking on water.
And the storm that hit that night was predicted to hit hundreds of miles from Sicily. Mr Borner (the captain of the other boat that rescued the people) thought that the curvature of the Porticello coastline should protect them.
Divers saw all hatches closed. (said by an Italian official)
The experts think that it was not one factor but a whole range of factors that caused the sudden and very quick sinking.
A Times investigation has found that an unusually tall mast, and the design changes it required, made a superyacht owned by a British tech mogul vulnerable to capsizing.
www.nytimes.com
