I did a very similar thing, with similar depth and length of water years ago.
I had a Honda CD185, manual 5 gears, with twin low slung exhausts (3 inches lower than yours) and a 15 stone mate as pillion passenger.
I kept it in 1st gear, around 3000 revs, 4 legs raised and stopped after we got through it, just to run the engine for a minute on high revs to expel any water. I remember the sound of my exhausts as they burbbled in the water!
Absolutely no damge.
As for you're CVT gearing, I'm not sure how it runs, guess its a continuous type gearing but if you can start off slowish with decent revs somehow and run at same revs or more, then I cannot see the exhaust will suffer, BUT, where or how low is you're air intake? Wouldn't risk it if air intake is postioned low.