More info?.....
I'd need more info on what type of mod you did for your supercharger.
But generically speaking, the crankcase ventilation on a 4 stroke motor usually vents to the air induction system so that any vapor can be burned off before going into the atmosphere. For a ski, this would be a good idea so that explosive vapors did not get trapped in your hull. But if you have the maker of your power filter so I can read about it, I can give you a better answer.:cheers: