A more thorough explanation:

Adventura is a historical term that means an adventure. It was used in Law Latin to describe the adventures of the sea, such as flotsam, jetsam, and lagan.

For example, if a shipwreck occurred and items from the ship were washed ashore, those items were considered adventurae maris or adventures of the sea. This term was used to determine who had ownership of the items and to settle legal disputes.