Bayesian crew should have battened down the hatches

On August 19, a superyacht, Bayesian, sank in a freak incident in the northern coast of Sicily near Porticello village.

Marine incidents do occur once in a while, but this one was controversial as the husband of the owner, Mike Lynch, dubbed Britain's equivalent to Bill Gates, was on a cruise to celebrate his acquittal from a serious fraud case when he sold off his company to Hewlett-Packard, allegedly at a much-inflated value.

The tragedy ended with seven casualties: Lynch, his daughter Hannah, Morgan Stanley International chairman Jonathan Bloomer, his lawyer and their spouses. Miraculously, most of the crew members, except for chef Recaldo Thomas, survived.

British dailies made much of the fact that Stephen Chamberlain, former vice-president of finance at Lynch's company, died after being hit by a car while jogging in Cambridge just two days before the sinking. He too was cleared in the fraud case.

What started off as a celebration cruise for the group ended up in a tragedy.

The Bayesian was a 56-meter-long luxury boat with a 72-meter aluminum sailing mast, reportedly the tallest of its kind.

It was launched in 2008, displacing some 550 tonnes and had three decks with six cabins, designed for luxurious cruising for up to 12 guests and a crew of 10.

The Bayesian was anchored in Porticello port when a freak storm developed and it was hit by a waterspout, a mini tornado, causing it to capsize and sink within minutes to the 50-meter-deep seabed.

A superyacht seldom sinks, and even if it did it would take a long time before water filled up its holds to cause it to capsize - imagine a multistory building suddenly toppling over into the sea in one piece.

The Bayesian rescue operation was extremely difficult.

With dislodged furniture blocking doors and entrances, trying to get to the lower deck to rescue people at a depth of 50 meters would have been extremely difficult. The loss of life, especially of those in bedroom cabins, seemed unavoidable.

So it is even more miraculous that most of the crew survived.

However, half the guests, except for Lynch's wife, a young mother, her infant and three other guests, died.

No wonder Italian authorities have opened a manslaughter investigation. A team of British marine inspectors is also conducting a parallel investigation.

Normally, when a yacht is anchored due to bad weather, its crew should mount a watch, around the clock if necessary.

The captain must ensure that all doors and hatches are tightly shut to ensure integrity, as water ingress due to storm or other reasons can change its centers of gravity and pressure, affecting navigational stability and making it susceptible to sinking.

Cabins are designed to be in watertight holds so that in the event one hold is flooded, the others are not affected and the vessel should still stay afloat.

As the Bayesian is a sailing boat with a high mast and huge sail, it has a deep keel to maintain stability, counteracting the force of the wind bearing on the sail.

It is not certain whether the keel was extended or retracted at the time, but if it were fully extended, the superyacht should not have flipped over that quickly.

Video footage shows the mast's lights going off first as the storm hit, minutes before the Bayesian flipped over and sank. It is believed water had entered the engine room and flooded the electrical system.

Had a lookout system been in place, the assigned crew member should, when the power was cut off, have immediately gathered everyone on deck with lifejackets on to prepare for an evacuation.

The fact that all but one of the crew members escaped unscathed but half the guests drowned indicates that this standard drill was not implemented.

There are some suspicions that the doors and latches were probably not securely shut either.

The causes of the sinking will surface once investigators have done their work or in any ensuing legal proceeding.

The Bayesian tragedy is receiving a lot of attention as some of those who died have just been cleared of fraud.

Sea cruises are enjoyable and often loved by celebrities and the super-wealthy.

They are usually safe as superyachts were built to very high safety standards, maintained meticulously and operated by experienced crews, with no expense spared.

This sinking is attracting attention and we can expect more stories to emerge.

For the technically minded, however, we believe it was caused by the carelessness of the crew, with a few critical errors defeating the supposedly foolproof system inherent in superyacht operational procedures.

It is a sad but vital reminder to all that stringent safety practice is essential for sea transport.

Veteran engineer Edmund Leung Kwong-ho casts an expert eye over

features of modern life