What's the deal with water backing up into the engine with the RRP and PFP pipes? Can you let the ski float in the water for any amount of time with the engine off without having to worry? Is it only in surf that it's an issue? I like to go to sandbars on lakes to socialize, but the ski needs to float for a few hours as it's too deep for a stand. Am I stuck using a b-pipe if I want that capability?