It's divided into two sections.
The first documents the work of the ancient boat and shipbuilders. It also displays the tools and instruments they used, as well as models of the different ship parts.
The second is a collection of archaeological treasures. You'll mostly find stuff of Roman origin, but there are also bits of boats, statues, ceramics and towers found in the waters around Monte Argentario and Giglio Island by divers in the '80s and '90s.
Photo: Ceppicone via Wikipedia.
Address: Piazzale del Governatore
15 Oct-15 Jun: every weekend: 10.30am to 12.30pm and 3pm to 7pm
Jun-15 Sept: open daily: 6pm to midnight
For more info: check out the official Maremma museums website