Starfleet commissioned the first Danube-class starships in 2368. Commonly called "runabouts," they are used primarily for short-range interstellar warp travel and missions, and are equipped with a warp-5 engine. Danube-class runabouts are typically used as auxiliary craft for starbase personnel.

Resembling a large shuttlecraft, the Danube-class runabouts are the smallest registered vessels in Starfleet. The cockpit has seating for four people, including a two-person flight crew (pilot and ops), and also contains a two-person transporter pad.

The runabout's aft section contains a living area, with bunks, a table, and a food replicator. It can readily accomodate up to sixteen passengers. The aft section design is modular, which allows the vessels to be constructed with mission-specific customizations.

All Danube-class vessels are named for rivers on planet Earth. (The namesake Danube River flows through Europe from Germany to Ukraine, into the Black Sea.)