Although there is a great deal of satisifaction in sinking a convoy while the escorts are left scratching their heads, I have found it beneficial to attack escorts using torps, and then engaging the rest of the convoy with the deck gun when feasible.
My general criteria for an offensive escort strategy is:
- It's night time or fog/rain conditions to reduce chance of air support
- There are only 2-3 escorts (depending on target composition by tonnage - tankers and cruise ship's vs low value freighters)
- I'm low on torpedoes. (less than 5 torps left)
I have two approaches to this depending on my boat's position. Ideally I try to get in front of the convoy so the lead destroyer is within 600 yards of me when I engage him. This gives him little time to react, and forces the convoy to take evasive manuevers. After the first torp hits the escort, I turn in the direction of the convoy (so stern tubes facing the convoy), launch decoys and go to flank speed for a few seconds, then drift. The remaining escorts typically make a bee line for my location setting up 2 easy "down the throat" attacks at less than 600 yards. Then I surface and attack the convoy with my deck gun which is already facing them with a minimum profile for my boat.
If I can't get in front of the convoy, I'll attack the side escort at close range, turn 90 degrees and then engage the remaining escorts as they race to my location. Again, launching decoys as bait works well. Just don't miss if you're down to your last torp.
