I got mine custom made.. its a king single in size, pvc floor and 100mm of side, and good heavy canvas top. Full length zips down either side, fine pvc mesh from about 1m from the top, and around the end, and if you tie it up it makes a ridge like structure.
I tie it to the bull bar with toes into the wind and never had an issue with water.
As many have said, only down fall is matress thickness. But if I used it heaps I would get a self inflating one..
Ill roll it out and take a pic..

Kallen Westbrook
Owner of
Westy's Accessories