Waterline is much higher when sailing, for sure. I doubt the compartments will make the boat unsinkable, but they should at least make it slow-sinkable. If a breach occurs above water level on one side, you'd do much as you would in any other boat - tack, and fast. This in an effort to bring your hull-hole out of the water in order to slow any flooding, and eventually make it possible to effect some type of repair. The watertight compartments inside the boat are to keep her from going down too fast. If the boat can't be saved, then at least maybe one would have more time to make an effective abandonment.

I'm still pondering the interior rubber skin or double-hull ideas. At least in the area forward of the main bulkhead.

Rereading Griffith's Bluewater last night, came across a place where he stated something along the lines that "one cannot head out to sea without taking aboard potential danger as a passenger". True. But you can only hope that this is a passenger who will cause no trouble while you are "out there", and do as much as possible to negate the effects if they do. The only way to avoid that is to stay in port. To that, I say No thanks.

Like another great sage said "I'd rather die while I'm living, than live while I'm dead.