Wilhelm Bauer first
She was built during WW2 and commissioned as U-2540 but scuttled near the Flensburg lightship as Allied forces approached.
After 12 years on the bottom it was realised that salvaging the boat (along with two type XXIII) was cheaper than building boats from scratch so she was raised and commissioned as a research boat, initially in the Bundesmarine then as a civilian vessel. After being released from service in 1982 she was bought by the museum and restored to WW2 condition.
As you approach the boat you can see how streamlining would have increased her underwater performance:
You enter through the forward torpedo room which has four of the original torpedo tubes left (the other two were removed during Bundesmarine service).
You then walk through a series of crew accommodation areas and wardrooms:
