A swim from any craft is going to suck on that river.
I wouldn't say it is easier to swim from a cat, although a lot of kayakers seem to think so. We are quite well braced into our frames, not precariously perched up there like people have asked me. While you only have your paddle to brace with (I'm sure this is simplistic) we have a lot of options. That includes highsiding all over the place, lots of frame to grab to keep you from going off/over, lots of tag lines and oars to catch if you do swim, and then with an open cockpit it's pretty darn easy to get back onto your boat.
If you do swim the #1 rule is to never leave your boat, it is the biggest PFD you have. It seems to me if a kayaker swims on that river you are SOL and better get to shore, while we tend to get back to our boat ASAP. The goal being to get back in the seat, which may or may not require a reflip. It is ideal to have your boat right side up so you are again rowing (duh), but an upside down cat is pretty stable although gear is going to get trashed.
Tag lines are life lines, although I have heard of one instance where someone had to cut one. They are flat webbing which do not tend to snag (do not use rope or tubular webbing). I do not use my side ones as flip lines as Josh does, I don't like them that long near my oars. There are always risks with every rigging decision, but the benefits of tag lines far outweigh the risks.
It's funny, I can't imagine running that river in a kayak. How do you guys see?!?! And you're down in that shit, instead of (mostly) on top of it. Yikes, that's too much for me.
I am a river, babe - I've got plenty of time, I don't know where I'm going, I'm just following the lines..... - "We are water" by Shaye