[seafarer]

In terms of sitting shallow, still and silent running and being detected:

- silent running does not make you silent, just much quieter, but still detectable at some level. If you want to sit and reload, try 100m depth, not 13m - you'll be far, far less detectable if still, silent running, and deep, not shallow.
- there is this thing called active sonar - works like a charm after 1943 when the allies started deploying much advanced sonar/asdic. It is also much more effective the shallower you are - again, go deep, don't sit shallow.

Also note that as you go deeper, if in the blast radius of a DC, the potential damage to your sub increase, not decreases. Water pressure works against you at depth and near a DC blast (that is, water pressure at depth will enhance the damage of a DC, not protect you from it).