The Leviathan Submersible Carrier has the appearance of a large, seagoing mammal. Large blast doors cover the entrances of the starfighter landing bay. Three laser cannons and a command pod are the only protruding sections from the flat deck covering the Leviathan's topside. Its original hull was designed to carry speeders, though many Leviathans in service have been upgraded to carry starfighters. Not only are they capable of transporting and deploying starfighters, they also maintain enough space for repair capabilities.

    Its vulnerability to fire from orbit and the extreme difficulty in transporting it from planet to planet has restricted this craft's usage. It was designed to be a seagoing fighter base immune to hit and run raids. The Leviathan could evade detection by travelling underwater, surfacing only to take sensor readings and send out and receive fighters. When combating an enemy in orbit, the Leviathan often employs sensor buoys. These devices float to the surface, activate at a pre-set time and scan for targets in orbit. The buoys and the data they hold are collected at a later time. The Leviathan is capable of scanning for targets as far away as high orbit, though it must come close to the surface to do this.

    This carrier has found its way into the arsenals of private armies all across the Galaxy. It is primarily employed by the Rebellion or by governments on water worlds as a mobile fighter base. Nonetheless, the Leviathan is now an outdated craft. These craft were effectively used by the planet of Bryx to defend itself from Imperial subjugation. After the planet had been conquered it took another three years before the last submersible carrier was destroyed, since it was forced to surface due to a faulty oxygen tank. Before shutting down, the firm Tirsa Wargear was restricted by the Empire from selling any new Leviathans. To stay in business, the company started to sell large numbers of spare parts. When the Empire discovered this, they shut the firm down, however most Leviathan owners already had an ample supply of spare parts for their craft.