Imperial Maritime Division The Imperial Maritime Division , also referred to as the Imperial Navy ( not to be confused with the Imperial Starfleet ) , was part of the Galactic Empire ' s Military that carried out operations on bodies of water of different planets . It was one of the important organizational distinctions of the Imperial Army , the ground forces of the Imperial Military . The Navy ' s most notable actions were fighting in the battle for the Montrosa Islands and the Liberation of Kashyyyk . Functions . It operated on oceans , rivers and urban waterways . When undergoing various missions , it utilized specialized aquatic vehicles , including destroyers , submersibles , and waveskimmers . History . In 0 ABY , the Imperial Navy fought against Rebel Alliance Military forces in the battle for the Montrosa Islands on the agricultural planet Reytha as part of a force led by Darth Vader . The Navy engaged other Rebel Navy units for control of the Montrosa Ocean and supported the Imperial Army operations in that battle . Years later , after the Battle of Endor , naval units also fought against Wookiee forces while trying to defend communication jammer s during the Liberation of Kashyyyk , though the Imperials were ultimately defeated in the battle . Organization . The Imperial Navy undertook aquatic operations for the Imperial Military . Its bases were constructed by ASP - 7 labor droid s and utility trawler s gathered resources such as food from aquaharvesters . The Navy used shipyards to construct a fleet of vehicles such as frigates , destroyers , transports , and anti - air destroyers . Although the Navy was powerful in its own right , it was also one of the weaker elements of the Imperial Military overall . Ship classes . Scout frigates . Within the Imperial Navy , there were aquatic scout frigates , repulsorlift craft sent to scout ahead on water or escort heavier vessels . Light Scouts were the most basic variant , armed with a captain and at least one gunner . The Standard Scouts succeeded the Light Scouts , and were built with a sleeker cockpit . Heavier - armed variants known as the Advanced Scouts . Destroyers . The Imperial Navy also made use of various aquatic repulsorlift destroyers . The standard Destroyer was clam - shelled in shape , and carried one pummel . The Heavy Destroyer variant was largely similar to the standard Destroyer , only with one additional pummel . Both variants were utilized by Darth Vader during the Reytha campaign of the Galactic Civil War . Cruiser . Likewise , the Imperial Navy made use of various aquatic repulsorlift cruisers . The standard Cruiser was boat - shaped with a single laser cannon . The Heavy Cruiser variant was largely similar , but possessed two laser cannon turrets and heavier armor . Anti - Air defense ships . The Imperial Navy also made use of Anti - Air defense ships , colloquially known as Missile Destroyers due to their common weapon choice , anti - air missiles . The standard Missile Destroyers had thick armored hulls and a single anti - air missile launcher . The Heavy Missile Destroyer variant possessed heavier armor and two anti - air launchers . Both variants were utilized by Darth Vader during the Reytha Campaign of the Galactic Civil War . Other . In addition to the vessels in the Imperial Navy directly related to combat , various vessel also served additional purposes . The Transport Ships were utilized to transport various ground personnel and vehicles to various locations on a planet via water , and were boxy / rectangular in shape . They served during the Reytha Campaign in 0 ABY . Utility trawler s were also used by the Galactic Empire to supply their various bases with fish and other aquaculture harvesting , with their models specifically resembling tanker ships of old . The Imperial submarine s were vessels that could submerge underwater and are capable of firing torpedoes at enemy fighters . Several were used during the Battle of Dubrillion against Rogue Squadron , when the Rebel squadron attempted to destroy a superlaser test bed that caught their fleet by surprise . Explorer Submergible s served a similar purpose , although it was meant for exploration and assault , possessing heavy weaponry to take out hostile lifeforms . Amphibion s were also utilized as early as the Battle of Corellia up to before the revelation of the Dark Empire . The Imperial Navy also had manufactured starfighters that were specifically capable of operating underwater , including the TIE fighter boat and , under the Krayt Empire , the Shark underwater fighter . They also utilized the Aquadon CAVa 400 s , modified versions of the CAVw PX - 10s for aquatic sieges . Waveskimmers such as the single person waveskimmer s and the AT - AT derived AQ - 5 Waveskimmer s . During the Krayt Empire and Fel Empires , the Imperial Navy also utilized the " Acklay " - class mobile fortress . Behind the scenes . The aquatic Imperial Navy was first mentioned in the for the 2001 video game " " , although was not mentioned by name in the game itself . Players get the opportunity to build Imperial Navy units in one of the Darth Vader campaign missions , and face computer - controlled units in one of the Chewbacca campaign missions . The missions and therefore the Navy appear in the game ' s 2002 expansion pack , " . " The vehicles may also be constructed in multiplayer matches by Imperial players . In Chapter 5 of the strategy guide , one of the members of " Galactic Battleground " creative team , Matthew Keast , implied that the Empire was at a disadvantage regarding sea - based operations . The branch was later given the name of the Imperial Maritime Division in the " " , as well as identified as being a branch of the Imperial Army .