Your best bet is a survival suit and a raft. Survival really depends on
the situation, in good weather, getting into a raft is not a problem.
But in bad weather, with heavy winds, rafts often get blown away before
you have a chance to board them. At least with a survival suit, if the
raft blows away, you still have a chance if you have to enter the
water. If you get into the raft, with a survival suit, even if the raft
keeps filling with water and you have to bail the water, you're got a
good chance of survival. But without the suit, and water coming into
the raft, you've got a problem. With a survival suit, in the kinds of
water you are talking about, you shouldn't have a problem, given a
reasonable time to rescus.

I've heard reccomendations that you put plastic bags over your feet
when getting into a survival suit, just like you used to do with snow
boots, they slide right on. Put a set of bags into each survival suit
bag.

I've got a raft, but I'm looking seriously at suits. I think their the
better line of defense. I'm not relying on the raft inflating properly,
right side up, not getting hung up in the riggers, and not blowing
away. I've got the EPIRB and a hand held VHF in a waterproof plastic
type bag the manufacturer makes. Take the flare gun with you as well,
and be careful with with hand held flares, you can end up damaging the
raft in the process.