Question: Naval Academy: Lesson 3 (Flak Gun)

[ValoWay]

hello,
i'm new to subsim games but managed to complete lesson 1 (navigation) & 2 (deckgun) of SH3's naval academy already.

My tactic in lesson 3 (flak gun) where you've to shoot down at least 5 of 10 planes so far is to immediately go for an emergency dive to get some distance from the pile and then to pick them off one by one from the sides.

Was working okayish so far but my problem is that the planes seem to disappear after a while.

My questions now are:
1) Is the game deleting the fighters & bombers on purpose when I get too far away from them?

2) In case it isn't deleting them and I set a course to get them back:

2.1) Will my watchman automatically report them, when he's on bridge, ofc ?
2.2) Will the fast forward thingy automatically be reduced as soon as the watchman (on bridge) sees something?

On the naval academy missions 2 & 3 I never could track my targets back again after I lost sight on them, that is why I'm asking these questions so that I can act accordingly.

Ofc, it's also possible that I just lost them but that's why I'm posting for clarification !!