If I had to summarise Season 3 of Das Boot, then it's clear that it's been a wasted opportunity. Simple as that.
The prior seasons were really quite good, albeit had certain flaws but at least set out to raise the storylines above clichéd warpaint by numbers drama. This season should have been the one to wrap up the story arcs although I've read just recently a short fourth and final season has already been planned.
What we have for this third season is as with the other seasons, a handful of parallel stories that overlap. There are really two prime stories, firstly a film noir-ish tale set in Lisbon with our token Gestapo man in a Bogard role, whilst in the sea we have a cat & mouse story between a German submarine v a British destroyer ship. The problem is that the British destroyer ship is led by a sociopath so it's clear how the chase will pan out, whilst the Lisbon detective story is just confusing & not captivating at all (if anything quite boring). Any attempt to try to humanise the characters too often came over as paperthin.
The only story of any interest for me was that of a young street pickpocket forced to serve with the German navy to avoid jailtime where we follow his redemption story. We have some other stories too, such as a German submarine captain's wife stuck in a loveless marriage, but again nothing of note. I'll leave it there.
It's disappointing to have to wrap up this season in such negative tones. The acting, direction and settings etc are still excellent, but it's lost its way, and quite frankly I thought the final couple of episodes were whitewashing of the reality of the era, it was all totally ridiculous (with some plot convenient and bewildering coincidences too). The writers all failed to understand what Das Boot should be about as per the original movie. Maybe less would have been more, and so concentrating on fewer storylines would have meant greater depth in them to give a greater realism.
I hope that Season 4 (if made) helps to rectify the problems from this season. The show deserves better and I assume would end this admirable series.