It seems like this is the sort of thing a god would need to do to inspire belief. But, Trump's still alive, so... happy coincidence?

I know a little about weather and accident investigations.
This is a rare accident with a very large superyacht. It's not that destructive downbursts and whirlwinds of hurricane force don't happen to ships large and small, sometimes resulting in knockdowns and foundering, it's just that, so far, it is extremely rare for this particular type of yacht.
One could say this could be due to reasonable care taken to keep these large sailboats out of dangerous wind conditions. The other take on it might be that the probability just hasn't resulted in the inevitable chance exposure happening. Since there are only a few dozen rigs and hulls of comparable design to the Bayesian, and another 300 yachts of similar class like this.
There is not a lot of exterior video of similar accidents. Posted below is something that may relate. The Encore, a 44 Meter  Aluminum  superyacht falling over at the pier in a severe microburst.

Knockdown in Aukland -
SY Encore,  Ed Dubois design
Sloop Aluminum
265 tons
44 m length
52 m tall aluminum  mast

Compare to this sinking-

SY Bayesian,  Perini Navi
Sloop Aluminum
496 tons
56 m length
74 m tall aluminum  mast

Though they are quite able to sail across oceans in very stiff breezes, these are not designed to be operated in greater than Gale force winds. The vessels take steps to steer clear of weather, and avoid certain routes and seasons in parts of the world. The very tall size for this type of sailboat, 50 to 70 meters tall, lengths of 48 to 60 meters and gross tonnage of 350 to 750 tons, does not make them more able to be in Hurricane force winds. There also can be downward directed bursts that affect how a vessel is knocked down and overcome its righting moment.
Either a down burst or a strong waterspout,  a bare mast and rigging of such great height 74 meters tall, generates massive force pushing it over. I have seen it suggested that with 100 kts of wind,  the wind force acting on the righting moment over the center of roll, would be more than 170 tons. That’s a lot pushing over a boat of ~ 500 tons. That force has a moment over the center of roll of the boat at about 37 meters. If the acting  force is great enough, the righting moment can be overcome for any boat to lay down at 70 to 90 degrees of heel for a period of time. From a few seconds to multiple minutes if the wind force is strong enough. The roll period is shorter than you might expect, some seconds only.

The lifting keel of 60 tons or so would have been up to reduce draft to 4 meters at anchor. Normally this is not a problem for reduced stability with reduced or no sails. But then again they were not designing it for hurricane winds while at anchor either. The heavy keel being up changes the roll period dramatically. Quicker to lay over, more time it will spend on its side before righting.

The amount of time it lays over is key. It probably only took a few seconds to fall over past 60° with the winds > 100 kts. Flooding can occur quickly, these designs are not wholly sealed watertight at certain companionways near the centerline.  They can be  subject to down flooding through hatchways or possible broken windows in the center Salons. Though you might think the restricted size of the companionways would be enough of a limitation, tons of water can enter quickly. Each ton of seawater changes the righting moment, slowing how fast the boat can overcome the inertia and angular momentum to roll up. Stay over long enough and even if it rights again, the partial flooding in these designs can sink them. The most at risk is the  massive central passenger compartment and staterooms, or flood an additional adjacent compartment through a hatch or bulkhead. This design has passageway watertight bulkhead doors that the crew must use at all times to traverse the vessel. They are required to be kept closed while underway, but are not always sealed when on a mooring.

The entire event only took 13 minutes from knockdown and breaking loose from the mooring, to sinking.

The wind burst may have been localized to the Bayesian and not the adjacent large topsail schooner. Though it has much smaller masts, the captain did not describe a knockdown himself, just severe wind. He dragged anchor, then launched his tender when it was over and he could no longer see the Bayesian anywhere above water. Rescuing 15 people who climbed into a life raft deployed as the Bayesian sank. The 25 man life rafts are automatically deployed as the boat submerges, but I suspect the crew was able to manually deploy the Aft Starboard life raft. They also managed to fire a single flare, possibly from the life raft.

There may be only a few dozen sailboats of this type and this tall, but these types of superyachts have been made since in the late 1990s, with most built in the mid 2000s and onward. They  were made by some of foremost yacht architects of the past decades. And well regarded as safe if operated within their limits, not many have sunk and most damage has been due to grounding, fire or other issue besides weather and stability. The design style has changed somewhat, so these heavy sloops and hull forms are not made quite the same shape. And rigs are all carbon now. Any deficiency in the stability design will be interesting to hear of. At stake are many tens of billions in value of the existing fleet.

Last edited by Johnny_Rotten (2024-08-21 02:44:24)

Bayesian - Perini 2008




And the similar masted but smaller 44m yacht Encore being knocked over at the dock in a severe wind. Note how quickly it falls over for a 300 ton sailboat.



Encore - Alloy Yachts 2004

Last edited by Johnny_Rotten (2024-08-21 02:04:13)

Who was Mike Lynch, the tech entrepreneur among the missing after a superyacht sank?
By Jordan Valinsky, CNN
Updated: 10:39 AM EDT, Thu August 22, 2024
Source: CNN

The body of Mike Lynch, the 59-year-old British tech investor, has been recovered from the sunken Bayesian superyacht, Italian interior ministry office Massimo Mariani told Reuters on Thursday.

Early Monday morning, a luxury yacht he was on was hit by a tornado and sunk off the coast of Sicily, Italy.

Lynch garnered much of his wealth from cofounding Autonomy, a tech company purchased by Hewlett-Packard, or HP, for $11 billion in 2011. An attorney for Lynch recently revealed that the entrepreneur’s total worth is around $450 million.

The Autonomy sale was one of the biggest British tech deals at the time but quickly went sour, with HP writing down Autonomy’s value by $8.8 billion within a year. The Autonomy acquisition was meant to fuel HP’s software business. Instead, the blockbuster sale has been bogged down by legal problems that recently culminated with a fraud trial.

Prosecutors accused Lynch and former Autonomy finance executive Stephen Chamberlain of scheming to inflate Autonomy’s revenue before selling to HP. In June, Lynch was acquitted on 15 charges — one count of conspiracy and 14 counts of wire fraud — in a San Francisco court.

The verdict came as a surprise to Lynch. “When you hear that answer, you jump universes. If this had gone the wrong way, it would have been the end of life as I have known it in any sense,” he told the Times, a UK newspaper.

Autonomy, founded in 1996, became Britain’s biggest software company and a member of the blue-chip FTSE 100 index. Lynch was lauded at the time by academics and scientists and was asked to advise the British government on technology and innovation.

The vessel Lynch was on, the Bayesian, is linked to his wife, Angela Bacares, who was among those rescued. Ownership records held by maritime information service Equasis show that the 56-meter yacht is owned by the Isle of Man-registered Revtom Limited, a company owned by his wife.

Lynch’s 18-year-old daughter Hannah is still missing, Mariani said, and divers are still searching the area where the vessel sank.

Earlier Thursday, a fifth body was brought to shore from the wreck of the boat, which sank earlier in the week. A CNN team on the ground saw Italian authorities move the body from a rescue boat to ambulances at the Sicilian port of Porticello.

–Reuters and CNN’s Barbie Latza Nadeau contributed to this report.