Couple of comments:
Not sure why you do not have sufficient radar or watch warning - either way just crash dive and the men are off the sail in a nano second.
Are you caught when transiting in TC? if so never go above 128. You will have plenty of time to crash dive.
You may lose speed zigging about - I prefer to go hard starboard when the aircraft commit but not before. I get both screws turning and get off battery charge when warned about incoming.
My gunners are the best, very experienced - but when I have more than 3 aircraft I crash dive and at 30m I go hard to starboard u/w. It works through every year. When they toss ahead of you in '44 you are already out of the path.
I also always level off at 50m. I never go deeper.
Hope this helps a tat.
And yes, they will locate you at night so be prepared ... there is a air coverage map which will show you progressive overlapping coverage though the war years. At some point you will always be a potential target of day and night attacks and they will get brutal.