I had some luck infiltrating a July 1940 GWX1.03 convoy last night, on the surface, in the dark. Call me Otto
. I was ahead of it, off to one side. It had three escorts, one either side slightly leading the convoy and one behind. I stayed at 2 kts and let the nearest front escort get fairly close, then went to ahead full (faster than the Black Swan was going) and pulled away from him and in towards the path of the convoy.
As it was dark I got away with it. A minute later I was just in front of lanes 1 and 2 of the convoy facing at right angles to their path, and the front escorts were drawing away. Sat there (even though I was going red on the detection display a lot!) and waited until I had two lovely big whalers in front and a large merch directly behind. I only had 5 eels left so went for two each for the whalers, stern tube for the merch, all on impact at around 4m depth.
At this point my Otto routine (or nerve) failed me and I hit C. Went to 150 metres then silent running at 2 kts, course roughly opposite that of the convoy but avoiding the rear escort. Got 2 lots of distant depth charges, then nothing! And then the payout - all three ships sank in about three minutes. Over 35,000 tons and not a scratch on me. Nice!
Not quite Otto as he would never have sat in one place or crash dived unless absolutley necessary but nearly.