Water in the clutch makes things tricky, in most deep river crossings you are slipping the clutch with some revs on to make sure it doesn't stall, but keep the speed low. Water gets in between the plates and you let the clutch out and you have no drive, then it must force the water out and your off. One of the clutch plates with 4 separate pucs may help with this. The forward facing snorkels restrict the depth of water you can ride through. You have to be careful you don't create a bow wave over the engine as it will go straight down the snorkels. An airhead should be easy to due drown though, pop off the float bowls to drain the carbs, drain the air box and pull the spark plugs. Even better with dual plugs, take the bottom ones out !
A lot easier than a 1200 adventure. I was with some guys on a trip to Macetown, near Queenstown in New Zealand. It involves 26 river crossings each way. The water level was a bit high and one of the guys drowned his 1200 GS. Difficult to remove the plugs. No air box drain. A PITA. ! !