Couple of things you can do.
1. After firing at the destroyer, immediately set up your shot and fire at the cargo ship. Don't wait until your torpedoes hit. If you wait, you're just giving the trawler extra time to close on you. You can be moving away before your first torpedo even hits.
2. After you fire the trawler already has a great idea of where you are. Go deep, 50m or so maybe, immediately after the last torpedo leaves the tube. If you can get your submarine icon to turn and stay green, that means you're not being detected. If it's red, you're detected. Solid green for long enough and the trawler should give up. Patience is your best weapon here.
3. Navigate your sub by heading using the compass instead of the course marker. Everytime you release the course marker, your speed it set to standard, which can be detected after you've managed to break contact. If he doesn't have you, you're a green sub, be patient and don't run but continue to maneuver.
4. If he's right on top of you at 50m, try sneaking down to 70. Remember you can't outrun him, you've got to be sneakier. If he's on top of you and your icon is still green, be patient and see what he does next. Playing without the icon is a lot harder. lol
5. You broke contact several times but he picked you back up when your engines went to standard.
Thanks for sharing the video.
