I was reading this article about this person's boat capsizing and self-righting afterwards. I am not much of an sea/ocean expert, so can someone explain why and when these boats capsize, they don't sink. I would imagine that they need to be kept very watertight. Looking at some of the photos on the Vendee Globe website, these boats look to be a fair size and look like they would sink if the capsizing does any damage to the integrity of the boat's structure.

Sailing alone for 46 days in the gruelling Vendée Globe round-the-world race, Mr. Hatfield's boat – the lone Canadian entry in the prestigious contest – capsized in heavy seas off Tasmania. Mr. Hatfield spoke to The Globe and Mail by satellite phone en route to Australia for repairs on his damaged boat. Here's how he described the experience:

Full news article here.

I am far from being a sailor, but my guess would be air trapped in the hull, and possibly built in buoyancy. I once read a book 'bout a group of guys to set out for New Zealand from OZ in a triple cat sailboat. Somewhere out there they rolled it over, ended up living in the upside down boat for something like two months before floating ashore back on OZ. They even cut holes in the "bottom" of the boat so that they could to into the hull and then back out on "deck"...

Most boats that I have experience with have all cavities in the hull filled with foam. If every open space in my boat was full of water, it would still float. Granted, there might only be an inch or two of the hull above water, but it wouldn't be on the bottom.

Welcome Newguy!

I used to work the oilfields too, hot dirty work...

Thanks.

Not too hot up on the Slope right now...

Probably not!!!

Self righting technology in Naval architecture involves the use of watertight 'voids' or compartments near the keel ( cold,bilge water accumulating compartments 6'2" californians barely fit in to repaint under the guidance of bigoted oregonian senior petty officers.)and the use of lighter, ie aluminium superstructures.
Older designs, like USCG 36535, my first 'command' employed a heavy, solid bronze keel paired with a double ender design and LOW CIG that took real genius to capsize in the first place.
They retired that boat on me, sent it on display with credit to another station and gave me a lousy 44' MLB- which I did in fact flip when the port engine head cracked. It seems this senior, oregonian petty officer forgot to connect both hot starts.then I was senior to him, and HE painted voids, another self righting feature of staying level headed in adversity or storms.

As a disclaimer,so asnot to get Old Man Neptune mad at me, ALL ships CAN SINK.It's a simple matter of putting enough stupidity in command to outwiegh anything that would normally float.

As single-handed racers of substantial length, these boats do indeed have voids filled with foam for added buoyancy. Being sail boats their keels can way as much as the boat itself. Hence the self-righting ability. Most skippers when they do go below do close the hatches during bad weather. This would prevent some water from coming in and swamping the boat. Evidently, as part of the training on the boat he did have it capsized with a crane to experience what happens. Never been that kind of situation but similar ones at the hands of others.

Anyone visiting Washington State should visit the lifeboat school on the Columbia. Rolling a boat is an experience few have, and fewer want to repeat. I think the record was 3 complete rolls in a 44' the local navy submariners were very boastfull of wht their 'boats' could do. Then they were taken for a 'ride.'