Hi Mel, you may find a lot of variability in this. Not being a strong swimmer, and realizing I actually LIKE air, I get the most flotation i scan find, like the Extrasport UT5. This jacket has a lot of easy adjustability The small kayak vests are for kayaks, where the kayak provides flotation as well, unless you swim... and that's when I want a lot of help getting back to the land of the air-breathing. The size of this jacket does not get in the way of my attempts at rowing, which helps too... Please report back on what you decide to do, yours, tom
Highest buoyancy Type III you can find that is comfortable to wear, so you'll actually wear it. I bring a Extrasport 27 lb High-Float on high water trips and sometimes wear it in the big stuff, but could never stand to wear it all day. I am 6'1 250 lbs and wear an 18 lb vest generally (Kokatat Ronin).
im a kayaker so i tend to wear those type of vests. i use astral myself. i have an aqua vest i wear most of the time, and a green jacket rescue vest i wear creeking/classV/high water. these jackets are not at all "kayak specific", don't let tom confuse you. the fact that you are in a kayak (a boat with floatation) has ZERO to do with the amount of floatation they provide. If you take a swim (what jackets are supposed to protect against), you no longer have the floatation of that boat, and the coast guard is not counting your kayak floatation as a supplemental piece of bouyancy...period/ just go look at the specs, compare apples to apples. fact is people trust green jackets to take swims in the type of class V water you will never ever see a drift boat or dory on. If boaters trust this jacket on log chocked class V+, it will be fine on your class II stretch. heck for class II, id even argue getting a big bulky rescue style vest is total overkill. green jacket is a pretty good vest, but honestly when I wear my low pro play boating jacket most of the time cause its very unobtrusive, easy to move in, doesn't feel like you are wearing much. for most rivers it does the trick. it doesn't have as much floatation as my green jacket but i have intentionally swam smaller rapids in it with no problems. if i anticipate a higher potential carnage factor ill wear the rescue vest but really the only difference between the two jackets is a couple pounds of floatation, a tether (something thats pretty dangerous in its own right) and a belay loop. the difference is not as big as most people imagine.
reality is, if you were ever in a a situation with a large feature (i.e. a huge pourover, seam, or a big hole), no pfd is gonna keep you afloat...if you get slammed to the bottom of the river by a big feature and thousands of pounds of water pressure, no pfd is gonna be your golden ticket out...you are coming up when the water is good and ready, not because of an extra lb or two of floatation.
i think the most important thing is that the vest is comfortable so that you will wear it every time. i never get in any boat without one on period. I've taken swift water rescue, done plenty of swimming in current, almost drowned kayaking a few times, so i take zero chances. being a fishing guide, I've found that getting people to put on the vest and wear it one of the hardest parts of the day. people are always trying to get the damn things off if they aren't comfy, so i by the most unobtrusive one so that people will just put it on and forget it. get one that feels good, fits well, and you should have no problems especially in class II.
just be forewarned, if you buy one of those goofy 80's style ribbed high float vest, everyone on he river will make fun of you, myself included =)
I second what Jeremy said. Having recently swam some big water in my type 3 astral green jacket (which i really love, great jacket that fits well and has lots of extras), i will bring a high float pfd along for those big water days in the boat.