Ok it is not final but here are the test install pics. I found it holds 200lbs but that is only because I cannot get it past the built in cooler.
Elbow fitting from Home Depot (79 cents)
This is the hose running under the stbd front cushionI cut it and it will be the fill end to the new sack.
This drain from the nose ballast to the center sack.
This is the fill center/drain hose.
looking from the bow inward
looking towards the front of the boat.
Threaded Mode