If you can find the hole, best thing is to stuff something into it, maybe a pillow even. I wonder what the most common hull breach actually is, a hole, or a crack or both. and large holes, you just dont have much time to do anything at all.
Then it is the basic design on interior bulkheading that can help. like a boat in a boat, have compartments that could flood but not sink the boat, if possible, or maybe that could slow it going down.
i sealed the mid aft bulkhead to the hull, and made it watertight. That bulkhead is about 6 feet forward of the stern. And the boat is 37 feet long. Then I disconnected the AC seacock and let the water come in as a test, at first it came in pretty quick, but after about 6 inches of water, it slowed down, and after 8 inches it was just trickling in, and the boat had sunk in the aft section about 5 inches? maybe or so. It seemed to me it would slow an actual sinking event. It took a long time to pump it out with the rule 2000.
See there is this plywood bulkhead of 3/4" and I sealed it very well, and it certainly held back the flooding water from getting into the main part of the boat. My thinking was maybe easier for a shaft or strut hitting something to break the hull open in the rear of the boat, than a hole anywhere else.
other place maybe the bow striking an object could crack open the hull. But up ther no good place to create a bulkhead, it would never be high enough.