I think you know that too . I agree that if completely breached open, there is a chance the Alpha 42 would sink. However, it will not sink by pulling a hose off a thruhull and stepping off the boat. That boat (and many catamarans) has 6 watertight compartments, as well as being built entirely of highly floatable core (in this case Nidacore, which is primarily air). I don't understand why you think a catamaran wouldn't have more core area than you - it has two hulls. And no lead.

So to sink one, one would have to climb into some pretty tight and hard to access places in both hulls, cut holes in those bulkheads at the top and bottom of them, open up all of the hatches and portlights and then pull hoses off thruhulls in both hulls. And hope the water and fuel tanks are pretty full. While bouncing around in the weather and/or health conditions that caused you to pull the EPIRB in the first place.

And then you hope it goes to the bottom and not sit just awash being a larger danger to others.

So while you could easily sink your boat by pulling a hose off a convenient thruhull (maybe even while sitting in the cockpit), you would not find it so easy on almost all catamarans - even if they are sinkable.

But I do agree with you on one thing - there is no way we will ever consider our catamaran unsinkable. That just isn't in any of our emergency or "plan B" considerations.

Mark