[sublynx]

Oh my. You really have a tough situation. More water and/or worse weather the next time would make survival easier. You need to lose the pinging. When I say lose I don't mean not hearing it, but the sound getting weak. When the pinging is strong you know they know exactly where you are. There's a "we see you" ping and a "searching" ping, and a "almost found you" ping - the only difference being the strength of the noise. You need to go fast and turn until you guess the pinging sound indicates they have lost contact. At that time you go back to silent running (or even 0 RPM but just for few seconds or tens of seconds) and you turn with the speed burst you still have from the higher RPM's. Turn to the direction you estimate gains the most distance to the escorts. Then you keep the course straight and steady if the pinging doesn't indicate they are pinpointing you again.

The small ship is probably a corvette. In my experience they often act as eyes for the destroyers with larger stock of depth charges. He might drop his own RPM's quite often to listen to you. You might consider trying to escape the hydrophone contact with the quietest noise - but first you need to use that prescious battery power to lose the pinging.