It doesn't seem right that water got in the CVT. I opened mine to put a new Hoca variator in, and was impressed not only by the rubber gasket for the cover, but also the snorkel tube for the vent that went somewhere up in the front. It should all be sealed enough to take a flood like that.
I disconnected the snorkel tube to let more air in, because I live in a desert and never ride my Super 8 in the rain, but now I'm going to hook the tube back up, and if it rains, I'll only ride the Super like a flash flood submarine.
Was the belt slipping, or the tire?
Check it out, it's only ten bolts, and the kick start, open it up and see what's what.
Like zomboni said, the WD stands for Water Displacement number 40, and it creeps to one millionth of an inch.