"Why do manufacturers use the crappy waterbed type fittings that barely attach?"
thats where I would use the glue!
"Take the other side off of what if I pull the bag out of where?"
uhh... the boat!
a fitting, for example, has two sides. It connects two "things." (i.e. a hose and a fat sac. ) I suggested you glue one "side" the other you could unscrew.
Thanks for the laugh!