No matter which mod I use I have never achieved decks awash. Periscope depth, radar depth anything under that depth but the boys either have me lower than decks awash or surfaced never in between.
It hasn't deterred me from sinking over 300,000 tons but I think I'll play with it a bit and investigate more about it.
I prefer to run the surface until forced down.
http://archive.hnsa.org/doc/firecontrol/parth.htm
