Only the black part of this rashguard is neoprene, but it's great when you need just that little bit of extra insulation.  Excellent for paddle sports because of the stretch of the side panels/arms.

It is very comfortable.  Keeps the sun from burning you and just enough insulation to keep you from getting cold after hours of snorkeling in 80 degree water.

I'm stoked kept me warm all day in Lake Erie splah Mich. 50 plus minus degree water on my personal watercraft 5/21/09! Early riding with just board shorts!