The problem would be when the water level in the cockpit was able to run into the boat via the companionway or a cockpit locker... It would take a long time but eventually it could sink... but in the meantime you'd have a lot of water below with all the attendant damage from that.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)