We visited the museum during a cruise ship tour in October 2018. The museum building is in a fortress on the eastern end of the city wall, close to the harbour. The museum exhibits were history artifacts of Dubrovnik as center of trade and shipping, competition to Venice, and ships for trading and warfare. A fine museum, worth a visit.
For more information see the website of the Dubrovnik Maritime Museum.
The part on part medieval history is shown by some contracts of that time. Among the ship models there was a skeleton model of a 16th century galleon. A major piece was a bronze cannon by the Turin workshop of Giovanno Battista Cebrano. The gun was regarded as a master piece of casting.
Several fine ship paintings were on display: a full rigged ship of 1809 by Antoine Roux, the steamer "Egitto" of 1853, the brig "Jansko" of 1858, the barque "Rado" of 1865, the lugger "Mladi Erzegovaz" of 1868, the steamer "Maria Antoinetta" of 1868 and the barque "Undine" of 1884.
Nearly all exhibits were behind poor glass with high reflection. It was difficult to get a clear view.