I mainly ride cable in Tampa and I have my board shorts or my full suit. Board shorts dry quickly as long as the sun stays out and my full suit is only for those really cold days where you question whether or not its worth riding to begin with. I don't ride much boat nowadays but I don't recall being in the water for that long before being pulled out again. It always depends on the person and their tolerance of cold water/temperature. If I am at the cable with intentions of trying new tricks with a high chance of crashing often, it's worth it to wear the full suit as long as it stays wet and keeps me warm. Even if I plan on having a relaxed day and just hitting rails with maybe a few falls but staying out there for a while, my full suit dries out and it ends up making me colder. I would usually just bear the chilly swims on the hopefully few falls I take and just sport my board shorts most days. Staying warm is pretty easy if you can make yourself hit every obstacle every lap. It keeps you warm if you stay busy and keeps your mind of the fact that your freezing! That being said, I enjoy when it gets colder here as its a change to the days where it's 90+ degrees air and the water feels hotter which is not even enjoyable. I did wear my full suit today as the water was pretty darn cold since it has been in 20s-30's past few nights but with a forecast in the 70's for the week ahead. Board shorts all day baby!!
And don't get me started on board shorts over full suit debate