as for the water going back in question; yes these pumps allow that, however, even if the discharge is below the surface of the water (as it is factory on my 02 XP) as long as you loop the discharge hose up above the water line (inside the ski) you will be fine. water will only go in it a few inches. Factory mine goes from the pump, then attaches to a approx 4 foot line. it loops all the way up under the seat up to where the fuel baffle is (flip seat up out of way) else you will hit your head on it 200x... When I bought my 02, the pump was so crammed with sand it didn't work, after I replaced it and the discharge line that was broken, it works... amazing. it's the auto sensing kind as well, although with how I ride (under water a lot) I should have just bought one that can run 'hot' all the time.... factory the pump is wired to be 'on' whenever the ski is on. no switch. but it only pumps when it finds water... not the entire time.... so there can be a significant delay between me sinking the ski (i've almost gotten a barrel roll) and it starting to pump... i just can't do too many underwater slides in a row... i've had it fill with water up past the VTS... almost every trip out! but the pump does its thing while the skis is going slow / idle... the bailers, if kept clean (pull them out, remove line and CLEAN then) pull a LOT of water out fast while your doing 25+
what i'd like is a little red light on my dash that lights up when I get over 3" of water in the hull, that way I'd know to take it easy on the submarine moves until it gets pumped out...