The MC75 cruiser, also referred to as the MC75 star cruiser, was a model of Star Cruiser in the service of the Alliance Fleet. One such ship, the Profundity served as Admiral Raddus's flagship during the Battle of Scarif. The MC75 was a former Mon Calamari city-ship converted into a war cruiser by the Alliance to Restore the Republic. The enormous vessel stood at 1,204.44 meters in length, and was powered by twelve Kuat Drive Yards Gemon-15 sublight ion drives repurposed to give the massive vessel a cruising speed to match starfighter escorts. These sublight drives were shrouded beneath the engineering plane of the heat-dissipating engineering structure.
The refits carried out at deep-space facilities afforded these cruisers reinforced battleship hulls and a weapon collar modification to hold primary weapons and shield generators. The armored forward hull rendered the ship's concealed deflector shield generators redundant, though a deflector shield emitter array was fitted to the aft. The MC75 boasted point-defense laser cannons, broadside turbolasers, heavy ion cannons, proton torpedo launchers, and tractor beam projectors concealed within a port forward of the weapon collar.[1]
An armored outrigger fin on the ventral hull held the command bridge pod and receiver array, opposite a dorsal communications transmission mast and sensor cluster. These blade-like fins, coupled with the vessel's tapered profile, were design choices intended to trigger primal fears of predatory fish among the aquatic Mon Calamari. The city-ship's former civic atrium was hollowed out and converted into a docking bay and starship service area, overseen by a hangar traffic control suite protected by overlapping shields and magnetic containment fields to keep oxygen and pressure regulated.[1]
There were at least two variants to the ship class including the MC75 Armored Cruiser and the MC75 Ordnance Cruiser.[5]
When the Galactic Empire occupied the ocean planet of Mon Cala, the native Mon Calamari began a mass exodus from their homeworld, taking many of their enormous city-ships with them. The MC75 cruiser Profundity, one of the many spaceworthy structures that operated as transports and passenger liners, was originally the civic governance tower in Nystullum, and was among the vessels converted into warships by the rebellion at deep-space facilities. As one of the first battle-ready ships, the Profundity became the flagship of Admiral Raddus, the former mayor of Nystullum,[1] and saw action at the Battle of Scarif[4] in 0 BBY.[6] The MC75 cruisers were only the first wave of ships to escape Mon Cala however, with other waves of starships following.[3]