Recent experience
It wasn't wide open ocean, but Queen's Sound in northern BC waters is pretty close in my books. We had our '77 33 out for about four hours in the slop left over from a brisk storm which had moved through that morning, leaving stiffish winds (20-30 knot) and swells in the 10-15 foot range. The boat held up well and handled nicely; she didn't even ride very badly. But after we ducked back into more protected waters and went below, she was pretty wet. There were no significant leaks, nothing loose, but the torque and twisting that comes with those big waves, combined with all the water over the bow, opens up every little gap and cranny in any thru-bolting in the hull, or any sort of fitting, and quite a considerable amount can come in... more the longer you are out.It wasn't anything dangerous at any point, and I understand it's not unusual in most fiberglass boats, but it's not something you would want to have to live with for long in any open ocean crossing. Of course, they're not all that rough all the time, but odds are you will run into those conditions at some point. It's a factor I plan to seriously consider when looking for the next boat.Cheers, and good luck.