The major part of this collection was accessioned through hydro-archaeological investigations of seabed locations, and consists of 1,055 objects.
It contains finds from Vratnik Bay, Glavat Point (end of the 1st and beginning of the 2nd century BC), Polače, Sobra (early 4th century) and Stoba (9th-10th centuries) on the island of Mljet. The permanent display features a small amount of the objects from most of the sites.
The finds from the sites off Glavat Point and Stoba on Mljet island are rather particular