i think their instructions make sense.
if the outside is closed, at depth, pressure will go through what I assume is a 1way valve into the balance chamber. On the way up, you’ll need to release this pressure, since gas will start to expand.
if the outside is closed, at depth, pressure will go through what I assume is a 1way valve into the balance chamber. On the way up, you’ll need to release this pressure, since gas will start to expand.