Even on a fine day wet clothes and wind will strip the body heat right out of you.
I tried Nylon sun pants, (stinger suit type), plus a kayak-jacket but on sunny days the dacron jacket stopped the wind but got too hot.
Then I tried a total wetsuit, too hot most of the time and very movement-restricting.
Finally I bought a Kokatat, breathing semi-dry suit and problem solved.
http://www.altrec.com/kokatat/supernova-paddling-suitThe fabric allows excess heat and moisture out without letting water in, the neoprene collar is much more comfy for all day wear than Latex full dry suit types.
Plus, if your boat is upturned at sea and you cant right it, or otherwise unplanned immersion this pup will protect you from exposure longer than anything else.
Easier to don than a wetsuit and if you are 'tween sizes get the larger as when sitting with knees bent and arms in paddle position extra material is needed to prevent tightening of the torso area.
"New York Kayak Company" gave great service.