The Trieste-class battleship was created to be both an effective ground and amphibious carrier, capable of transversing not only land and sea, but also submerge itself completely underwater. The Trieste-class is well-armed, possessing an arsenal comprised of 6 Torpedo Launchers, 7 Missile Launchers and 8 Machine Guns. The Trieste also has two large mobile suit hangers, each with a hatch located at the front of the ship, and capable of carrying a sizable complement of 20 mobile suits.
Captained by Zakott Dattonel, the Trieste served as the base of operations for Ennil El as she started her pursuit of the GX-9900 Gundam X piloted by Garrod Ran. When the ships compliment of DT-6800HM Daughtress High Mobility mobile suits were destroyed, Zakott used the large ship against the crew of the Freeden only to be destroyed in a vapor explosion caused by Garrod Ran.
While attempting to settle a salvage right in the Sea of Lorelei the crews of the Mirage and the Rosa Rosa take part in a competition to see who can salvage the most valuable find from the ocean floor. During the competition, Rosa II is attacked by her own crew and takes refuge with Rick Aller in a sunken Trieste class ship. Much of the interior is flooded, except for the cargo hold which contains a single black Gundam X and its pilot Kai in suspended animation. The ship is destroyed when Kai awakens and uses his Gundam X to fight off the mutineers of Rosa II's crew.