RE: New ballast system
I can't get y head around this to to see how this could work in a model sub. Is this bag designed to go in the dry watertight compartment or in the wet compartment? I am guessing it is in the wet compartment because if it were in the dry compartment there would have to be a change in pressuure with that comartment . It looks like the only time there will be air inside the bag is when you start off. When you fill it with water the air escapes and when you drain the waer out with the pump the bag collapses. When you now switch off the pump, the bag will remain collapsed even if the air pipe is above the water.