So, how many escorts have you had bothering you at one time?
My record stands at five, four destroyers and an armed trawler. They held me down from 18:00 to 01:13 the next day, first one Destroyer got lucky and got a whiff of me as I was leaving a convoy I'd just run into, the D/C run did a fair bit of damage, so I was left bailing out, which gave him a better fix on me. He then, of course, called in all his friends, two of them, who came in to join the party, then, as it grew dark, another destroyer showed up just as the first destroyer ran out of depth charges. No rest for me then.....aaand then just as the second destroyer runs out of D/Cs, my old nemesis the Armed Trawler shows up...but thankfully this one didn't have ASDIC (although at least two of the other destroyers did and they REALLY made up for the Armed Trawler) and so his runs mostly went wide.
I'm running on about 78% realism, have done from the start, so I watched the Destroyers playing around on the surface...it was quite amusing to watch four Destroyers try very hard to be in the same place at the same time. Lots of stopping, reversing, getting stuck over depth charges as they went off (although the D/Cs were deep enough to prevent damage to the ship

)
They kept me down well though, and shook me up a little bit, Boy was I glad to get up to fresh air when they left, heck, I didn't think they ever WERE going to leave, because even though they'd run out of D/Cs, they were still pinging away, and since two were pinging and two were listening whilst the fifth D/C'd, there was just no getting away from it except to go deep, go quiet and break to port or starboard whenever one came overhead. According to the workers at Wilhelmshaven, my hull integrity was at 56% when I finally returned to base, with 48Ks worth of tonnage under my belt. Uncle Karl must have been pleased, he gave me a Ritterkreuz.
Alfons 'Eskorte' Elric - U35 - Total Tonnage in May 1940 = 149004