When the imponderable becomes reality

An analysis of the Bayesian case

Rivers of ink have been written and too many words have been spoken, mostly out of turn, about the well-known affair of the Bayesian’s shipwreck, mostly by people who may be experts but are essentially seeking personal media exposure. Let’s try to shed some light on what happened.

The angle of down-flooding

Of the many statements, only that of Stephen Edwards, a former Bayesian captain, offered an authoritative and supportable opinion, stating between 40° and 45°, the Bayesian’s angle of down-flooding, an important detail omitted by the other commentators.

This is the angle of heel at which water begins to enter the Perini Navi yacht, usually through the engine room or accommodation ventilation shafts, when they are not closed. With the HVAC (Heating, Ventilation and Air Conditioning) systems and the generator running, the ventilation flaps must be open, and the yacht could quickly flood if the heel is greater than the angle of down-flooding.

The Italian Sea Group’s statement

The Italian Sea Group, which acquired the Perini Navi brand after the bankruptcy events, provided some interesting technical data, some of which we report below.

The statements also include that of the CEO of the Italian Sea Group, Giovanni Costantino, who – although only indirectly involved – wanted to defend the legitimate interests of the company, but from the outset blamed only the captain and the crew, declaring that the yacht would have been unsinkable had it not been for human error. Given the tragedy of the dead and the survivors, this was an own goal from a communication point of view.

Perini Navi’s future

As for the future of Perini Navi, we are pleased to learn that the first days of December 2024 saw the technical launch of the Perini Navi ‘Katana’, a 60-m vessel commissioned by Larry Ellison. The construction was suspended after the shipyard’s financial difficulties led to its bankruptcy and subsequent purchase by TISG. It is currently unknown if the American tycoon is still the owner.

Speculations on the sinking

Returning to the story of the Bayesian, it is believed that the sinking – which occurred before dawn on 19 August 2024 – was caused by either a waterspout or a downburst phenomenon.
Both phenomena are recognized as potentially dangerous to ships, but there are no aggregated data or publicly available statistics on how many superyacht accidents specifically related to waterspouts or downbursts occur each year, precisely because they are so rare.

In this case, those who might know more, the surviving crew and guests, the divers who recovered the bodies and the investigators, are keeping silent, while everything else is more or less suggestive conjecture.

The current situation

At the moment, the Bayesian has still not been raised from the seabed. The recovery of the sailing yacht from the bottom of the sea has been postponed several times, apparently because of the difficulty of bringing it to the surface without destroying elements crucial to the investigation.

As we write, news has reached us that the prosecutor in charge of the investigation has approved one of the proposed salvage plans for the spring of 2025. Before the S/Y is parbuckled and brought to the surface, the company in charge will cut the mast at the level of the boom. After studying underwater footage and the position of the mast, with part of the rigging stuck in the seabed, it would be extremely dangerous to right the yacht with the mast.

The fuel tanks will be emptied after the salvage operation has been completed, to avoid the risk of environmental damage caused by emptying the tanks with the hull submerged. This was decided by the public prosecutor’s office in Termini Imerese (a town near Palermo), after a meeting with investigators from the Coast Guard and lawyers appointed by the insurance consortium that took out the policy with the company managing the yacht on behalf of the owners.

Only when the S/Y can be analyzed in detail by experts, and both the results and the statements of the protagonists are made public, will we have a better idea.

Consequences on megayacht design and construction rules

The Bayesian is a huge motorsailer and not a sailing boat. To be clear, when a normal sailing boat ‘puts the mast in the water’ (i.e. heels 90/100° and more), it is capable of self-righting.
We have no doubt that a sailing yacht like the Bayesian was designed and built in accordance with all the safety regulations laid down by the authorities, so it is likely that the investigation into this terrible event will result in new design and construction rules for megayacht design in the future.

Keel configuration

One of the first, and false, accusations levelled at the captain was that he had not lowered the centreboard to increase the righting moment. The aspect of the yacht’s Angle of Vanishing Stability (AVS) – or Limit of Positive Stability (LPS) – was considered by the former Bayesian’s captain Stephen Edwards (and not by many other experts): he put it at about 75° with the keel up and about 90° with the keel down (as said, at anchor the down-flood angle of heel is more important because the watertight hatches are necessarily open).

We should add that in the case of the Bayesian, the ballast of around 200 tonnes is placed under the hull and not in a bulb hanging at the bottom of the keel blade, as is the case with most sailing boats. As a result, the centerboard, which weighs around 60 tonnes, is only lowered to limit drift when sailing, while the righting moment increases when the yacht is sailing. This type of keel configuration guarantees much greater safety, at the expense of some performance under sails, because there is no risk of losing the ballast placed in the bulb in the event of grounding or collision with semi-floating objects.

An ‘incredible’ event

In its rebuttal to the NY Times investigation, TISG stated the following: “The calculated angle of heel at 60 knots of crosswind is about 18° and, therefore, cannot cause flooding under appropriate conditions (at 80 knots of wind, the angle of heel is about 28°). In order to achieve the claimed water ingress of 1 tonne per second, the engine room ventilation opening would have to be completely submerged at a depth of about 3 m, and this condition cannot be achieved even with complete down-flooding (heeling of 90 degrees or more).”

Only the future will be able to give us technical answers to an event that is, to say the least, incredible, with overtones of mystery and conspiracy. We have been struck by a series of what – in the present state of human knowledge – we can only call ‘coincidences’.

Coincidences

There are 3 main ‘coincidences’ to be considered:

1. There was a meteorological event that rarely hits a yacht.
2. There were two deaths within hours of each other. Owner Mike Lynch, known as the ‘British Bill Gates’ and one of Britain’s best-known entrepreneurs, died in the shipwreck a few hours after the apparently unrelated death of Stephen Chamberlain, his friend and right-hand man.
3. Among the Bayesian dead are Jonathan Bloomer, the chairman of Morgan Stanley International and Hiscox insurance company, and Christopher Morvillo, a lawyer with the well-known law firm Clifford Chance.

This series of tragic events left many questions unanswered and fuelled speculation about possible links between Chamberlain’s death and Lynch’s disappearance, given that Autonomy’s IT products were sold to certain intelligence agencies. However, the British authorities have stated that there is currently no evidence of a direct link between the two incidents.

The edge of improbability

The Bayesian is a 56-m long superyacht launched in 2008 under the name Salute. It was designed by Ron Holland, a respected designer of megasailers, and built by Perini Navi, one of the most qualified shipyards in the world.

Although the design of the 56-m Perini Navi was modified to change the rig from a ketch to a sloop with the tallest existing aluminium mast (72 m), the yacht had been certified for ocean sailing; after 16 years of cruising on all seas and in the most difficult weather conditions, we still have no valid technical reason to justify the sinking of the Bayesian in a few minutes, which is why human error was thought to be the cause.

Whatever the series of causes that will hopefully be uncovered, when we think of the plausible probabilities that motivate it, we are truly on the edge of improbability.

The origin of the name

Finally, a final coincidence that sounds almost mocking: Mike Lynch had made his fortune by studying probability in statistics since his undergraduate days at Cambridge University, where he obtained a PhD in Applied Mathematics and Computer Science.

His thesis was on Bayesian statistics, which is particularly suited to dealing with situations of high uncertainty, where information is limited and subject to rapid change. The application of the theories formulated by the English mathematician and philosopher Thomas Bayes (1702-1761) was the basis on which he built his empire of Autonomy.

Thomas Bayes and his theories were a beacon for Lynch, so much so that he dedicated his beautiful Italian yacht to him, renaming it Bayesian.