[PavelKirilovich]

In 1942 I recall playing "tag" with a number of destroyers as I was worming my way into Loch Ewes. Running at periscope depth on standard propulsion (IE: Not running silent) at one third speed caused them to pick up on me only when they came within ~500m. At 1/3rd it is a joke to rattle back to silent running if they get about a kilometer off according to your hydrophone operator.

This allowed me to get into Loch Ewes, torpedo an escort carrier and a cruiser, sink a T3, and leave - and I was being pinged constantly but the destroyers never made attack runs as I did this all at PD.

Then I got jumped by the RAF while recharging batteries at night on a glass-smooth sea. Decided to fight them with the Flak guns. Didn't go so hot. Crash-dove and then spent the remainder of my patrol popping up for about an hour each night to try and air out my boat and recharge batteries before having to submerge again and creep along at ahead slow to conserve battery power.