The sea has played an important role in the history of the town and this is acknowledged in two galleries within the museum, the `Ebb and Flow' exhibition and the Maritime Gallery. The predominant feature of this gallery is the history of the lifeboat in the town, from its first unnamed boat in 1852 (originally provided by the Shipwrecked Fishermen and mariner's Benevolent Society) up to its present brand new life boat, the Hayden Miller and its new lifeboat station. Also featured in this gallery are the history of piracy, the story of HMS Tenby and the history of the Tenby Air Sea Rescue Unit. All of these are illustrated through text, pictures, paintings, models and original artefacts.

Caldey Island was once rumoured to be a rendezvous for pirates and documents from the latter half of the 16th century tell of the fear of the islanders. For centuries piracy continued in the Tenby and Caldey area.

Towards the end of the 18th century, John Paul Jones became the most notorious pirate in these waters, often stopping at Caldey and Waterwynch to supply his ship. One of his officers, nicknamed `Leekie' Porridge came from Tenby and there is a display about this character as well as other pirates connected with the area at the museum. There are also pirate treasure trails and quizzes to test your piratical knowledge.