Other things...
Can't say I've ever been to a launch that had trees or power lines. The only places that I've seen those were too small of a lake to launch a sail boat in!Another thing you do want to check is the depth, ahead of time. You set the boat all up, get it all ready, and then find out that you'd have to back half your truck into the water to get the boat off the trailer. Sailboats draw a lot more then a power boat usually does.Make certain there's no drop offs either. Quite a few people lost a trailer into Lake Michigan, myself included, because of this. The water was excessively low, and it wasn't posted that there was a six foot drop off eight feet into the water. Four hours later the trailer was out of the water, a seventy five dollar lesson.It's mostly the same as launching a power boat, just everything is exagerated by the size of your boat. The back end will swing more when you turn the wheel, because it sticks further off the trailer, turn opposite, etc. Just line it up as straight as you can, make certain that you have some nice gripping tires, and hope there isn't too much alge for your tires to slip on. It's easy getting the boat in, but pulling 4000lbs of boat and trailer out of the water can be a bit difficult.Josh