This appears to be the location of the engine room ventilation. That would certainly let water in at 88 degrees. Perhaps there is a procedure to seal those hatches when rigged for sailing. Was the vessel sailing or motoring during the storm? If motoring, these hatches would have been open.
If hit by a wave from the beam that cause them to lay over, well there is certainly a lot of glass on the side of the house.
From what little I have seen, cargo ships have a fairly uniform side profile both above and below water; the have all the shaping of a rounded brick.
Sailing ships, which I once had considerable interest in, tend not to. In particular, the mast of the Bayesian alone represents a considerable surface for wind to apply a load forward of the middle. It also looks to keep the foresail wound around its rigging, adding more area for the wind to act on. If all other loads are balanced, those alone will turn it downwind.
There are also two forward doors for small watercraft to be aboard and some witnesses thought it went down by the bow; this is in keeping with an early speculation that an access door had been left open.
It looks like there are already efforts to muddy the water:
But Mr Costantino, CEO of Italian Sea Group - which owns the company that built the ship - insisted it took 16 minutes from the moment the boat was caught by the wind and began dragging its anchor before it finally sank, which should have given the crew enough time to warn passengers.
Dragging the anchor doesn't normally cause a ship to sink, so the 16 minute reference makes no sense. It makes sense to know how long it was from the time it began taking on water until it sank.
I can imagine that it was mainly OK dragging the anchor by the bow, but at some point the anchor line was lost, allowing the drag on the mast and forward rigging to turn the ship sideways and heel. If a forward garage door was open that would allow the door to go under, flooding the forward portion and maybe the rest of the yacht; few details on interlocks and watertight doors.
I would be surprised if it was a knockdown with no sails up, even with the keel up. That is still a more than literal ton of weight.
euronews says:
A source briefed on the investigation, however, told Corriere della Sera that divers who went down to inspect the wreck found the mast in one piece, with the boat intact — its hull unbreached, its hatches closed, its windows in place.
Sure, the knockdown is survivable for most vessels. The trouble is that on a 40 foot wide vessel there is a lot of potential for fall injury and death.
It is possible the forces from the anchor could have breached the hull. The anchor transfers forces to the hull through a winch. It's possible the foundation failed and caused a breach. The anchor is also attached to the hull via weak link. Maybe the weak link wasn't weak enough and that damaged the hull.
I don't see any probability on a downdraft strong enough to push the bow down and sustained enough to hold the bow down.
A sudden change in wind direction could cause the boat to make contact with the anchor chain.
A boat doesn't float in aerated water. There was a aemi-submersible oil rig that capsized some time back because the well had a blowout and the gas aerates the water enough that it lost buyancy.
The depth of the aeration would need to exceed the freeboard (caveats about waves and heeling) to get them to sink. The little ones that I have seen in the news are because someone cranked up the anti-ice aeration too high, so the water density was lowered all the way to the aerator depth. I think people have drowned this way from falling into water treatment aeration tanks.
I would not expect sufficient churning of the water to do the same to a yacht from a water spout; perhaps a deluge of water directly onto it? Even that requires open hatches.
Google isn't aiding in finding a boat sinking at the dock from aeration, but this is one amusing thing I found about dealing with an upset condition. Who would have guess that bolting ladders with the rungs vertical on the sides of the cabin would have been smart? Sure people make fun of it, but it pays to be prepared.
There are a bunch of Navy ordnance videos where a explosion amidship lowers the density of the water enough that the hull, damaged by the blast in the uplift portion, if finished off when the remaining buoyancy is at the bow and stern and folds it like a church luncheon chair because the middle isn't being supported by the new foamy water installation.
