I am going to plumb a locker sack into my ski locker. I will be using the Fly High Rear Seat sack - it's fits perfect.
I have 3 drain plugs in my direct drive. 1 on the transom and 2 under the engine.
I am going to suck water from one of the drain plugs under the engine to the sac using a simer pump. When I want to drain the sac, can I reverse the pump and pump water out of the same hole in the bottom of the boat?
Also, can I "tee" the vent line into a higher elevated point on the bilge line. I would be putting a check valve on both the vent line and bilge line so that one can not back flow into the other. The check valves would be "south" of the "tee'd" junction.
Sorry, not the drain for the bilge pump, but the hole in the bottom of the boat that which you will pump in and out of? I/m guessing your boat has the over-size bilge plugs, 3/4 NPT maybe, instead of the typical small, maybe 1/2 NPT, drain.
If you use a simer pump you must be able to tell when the bag is empty... therefore I would drain it out a hole above the water line. Running simers when the bag is emplty will blow fuses (or worse) melt wires...trust me...