There are three floors of maritime exhibits here but the highlight is the reconstructed Bremer Hansekogge, a merchant boat from 1380 discovered during dredging work on the Weser in 1962 and reassembled (in part) from pieces rescued from the deep. There are also three boats outside on the harbour that can be visited as part of admission (note that others, such as as the Technikmuseum U-Boot Wilhelm Bauer, have separate entrance fees).
The museum is undergoing a major renovation of one of its buildings through 2020, and so admission is at a reduced rate until then.