"Bayesian" s/y sinks in Palermo

[franksingleton]

We can only speculate at this stage. BBC R4 news says that smaller boats survived.
Was Bayesian just unlucky in being at precisely the wrong place at the wrong time?
Were hatches open to keep people cool at night?
Presumably, there was air conditioning?
Is there a design problem?

There may be clues here!

“The fundamental difference between these 2 schools is their interpretation of uncer-
tainty and probability1: the frequentist approach assigns probabilities to data, not to hypotheses, whereas the Bayesian approach assigns probabilities to hypotheses.”

 

[Porthandbuoy]

That's my point how do you prepare for such an unusual event?

Discipline. Unless tied up alongside ensure all watertight hatches and doors are closed, secured and keel is down for maximum stability. I’m not implying that’s why she went down, we’ll have to wait on the MAIB report for that, but prepped for going to sea like that would have given her the best chance of righting.

 

[Mark-1]

One that could do for them would be a problem for any boat. Even a medium ship would be in trouble, you’d think.

I would guess any MAB or AWB would cheerfully survive two minutes on its side with wash boards in and hatches closed.

 

[Mark-1]

It's just occurred to me that the chef was recovered early in the process. Which suggests to me that all of the crew escaped the boat (even if one died). Whereas only half the guests got out of the boat.

Were the crew all up at 5am, perhaps running around closing hatches? Familiarity with the boat? Youth and therefore greater physical ability to climb out? Easier escape from crew quarters?

 

[Skylark]

Something that I have noticed is that they are using local firemen divers who are diving on air on a no stop basis giving them a maximum of 10 minutes bottom time. They need to get specialist divers who are qualified to use mixed gas apparatus which will extend their bottom time. There should be military clearance divers and commercial divers in Italy capable of doing that.

I'd noticed this, too. It makes no sense to no-stop dive to 50m on air. Not just for decompression loading, think about the affect of nitrogen narcosis, knowing that you're quite likely to find a body floating inside the wreck. An appropriate trimix would give a clear head and significantly longer, safer time underwater.

 

[Baggywrinkle]

It's just occurred to me that the chef was recovered early in the process. Which suggests to me that all of the crew escaped the boat (even if one died). Whereas only half the guests got out of the boat.

Were the crew all up at 5am, perhaps running around closing hatches? Familiarity with the boat? Youth and therefore greater physical ability to climb out? Easier escape from crew quarters?

 

[flaming]

It's just occurred to me that the chef was recovered early in the process. Which suggests to me that all of the crew escaped the boat (even if one died). Whereas only half the guests got out of the boat.

Were the crew all up at 5am, perhaps running around closing hatches? Familiarity with the boat? Youth and therefore greater physical ability to climb out? Easier escape from crew quarters?

If you look at the account of the other captain, they were aware that weather was coming, but not how serious, for some minutes beforehand. It therefore seems more than probable that the captain would have called for all crew to be on deck in case they were needed if the boat started to drag etc.

 

[mainsail1]

To me, the elephant in the room is the huge mast. If they designed these extreme boats as a ketch I guess the main mast height could have been very much shorter with all the stability benefits that should give.

 

[Mark-1]

If you look at the account of the other captain, they were aware that weather was coming, but not how serious, for some minutes beforehand. It therefore seems more than probable that the captain would have called for all crew to be on deck in case they were needed if the boat started to drag etc.

That does seem quite likely. Although, I assumed some of the crew would be purely domestic and not people you'd wake then the weather got bad. Maybe that's false. If you've got 30 hatches to close (or whatever they do in response to bad weather) maybe everyone gets woken up and mucks in.

Apropos of nothing, the video above says the keel *was* part of the ballast but gives no good source for that.

 

[Mister E]

Discipline. Unless tied up alongside ensure all watertight hatches and doors are closed, secured and keel is down for maximum stability. I’m not implying that’s why she went down, we’ll have to wait on the MAIB report for that, but prepped for going to sea like that would have given her the best chance of righting.

Do you do that every time you anchor?

 

[Mark-1]

To me, the elephant in the room is the huge mast. If they designed these extreme boats as a ketch I guess the main mast height could have been very much shorter with all the stability benefits that should give.

If they did that the designer would simply put less ballast in to compensate. If it transpires that there wasn't enough ballast for the mast then fair enough but I very much doubt that will be the case. The problem here wasn't that the boat went on it's side in a tornado, the problem was it let a load of water in when it was on its side.

 

[Mark-1]

Do you do that every time you anchor?

Of course, if this boat had been in a marina it would still have ended up on its side.

 

[Mister E]

Of course, if this boat had been in a marina it would still have ended up on its side.

Nobody sets their boat up for sudden tornadoes in the med.
The reality is that a thunderstorm was forecast not hurricane force winds. It is not the Southern Ocean.

 

[Porthandbuoy]

Do you do that every time you anchor?

Yes.
Cockpit hatches giving access to the engine: closed.
Bottom washboard in as a minimum, (usually both boards in and the hatch closed to keep the midges out).
Sheolin doesn't have a garage on the waterline for jet skis and the like, nor does she have any watertight bulkheads with hatches that can be secured.

 

[Bouba]

We had a waterspout that came ashore and ripped all the trees out…if one crosses the path of a boat I don’t see how you could survive….they are quite narrow so a boat nearby might escape unscathed

 

[chriscallender]

Discipline. Unless tied up alongside ensure all watertight hatches and doors are closed, secured and keel is down for maximum stability. I’m not implying that’s why she went down, we’ll have to wait on the MAIB report for that, but prepped for going to sea like that would have given her the best chance of righting.

Agree. We are talking abut a professional crew on duty for watches at anchor, warnings in the weather forecast, top of the range radar available to see what is coming in etc. I'm sure that configured suitably she could easily have survived hurricane force winds/tornado/waterspouts and also that they saw the storm approaching, but were thinking it would be a normal thunderstorm which would be a trifle in something that size. Actually the 15 guests and crew that were rescued were most likely up and about doing their jobs or awoken by the storm and out of their cabins watching the weather for a while when disaster suddenly struck.

I'm pretty sure there will be lessons to learn for the superyacht industy when the report comes out. The details won't be too applicable at the level most of us are sailing at. But discipline and being prepared for unlikely but severe eventualities are pretty universal.

 

[webcraft]

Downflooding angle and the angle at which righting moment becomes negative are two different things.

Indeed. The AVS of the Contessa 32 is 178 degrees.

- W

 

[AngusMcDoon]

.

 

[Paddy Fields]

I'd noticed this, too. It makes no sense to no-stop dive to 50m on air. Not just for decompression loading, think about the affect of nitrogen narcosis, knowing that you're quite likely to find a body floating inside the wreck. An appropriate trimix would give a clear head and significantly longer, safer time underwater.

It’s a body recovery operation. No one is coming up alive.

They are at 50m, which means 6 bars of pressure. Ear drums would have exploded. Total disorientation. Ppo2 of 1.2 for prolonged time means convulsions and thus drowning from oxygen toxicity. Even if you could bring them up, it would be a very slow decompression assent.

 

[Cheery]

Caribbean hurricane season is 1st June until end of November. Peak of the season is early September.

When my son worked in the BVI they closed most tourist places for the whole of August and most of September. He left the year before the double hurricanes 2 weeks apart.