The Marines, also known as SpaceOps, represented a distinct component of the Alliance to Restore the Republic's Special Forces during the time of the Galactic Civil War. These Marines, composed of resilient and seasoned soldiers, received specialized training for combat scenarios occurring on starships, within space stations, and in zero-gravity environments. Their standard equipment consisted of lightweight weaponry, carefully chosen to minimize potential damage to their surroundings during engagements, and they typically wore either light armor or specialized armored spacesuits.
The Marines, alternatively called "SpaceOps," functioned as a specialized military arm within the Alliance to Restore the Republic's Special Forces structure. The designation of Marine Regiment was given to the first regiment within each of the ten SpecForce divisions. Training for Marines centered around combat operations conducted aboard starships and space stations, with typical missions including the boarding and seizure of enemy vessels, the defense of their own ships against boarders, or serving as the initial assault wave in spaceport landing operations. Beyond their combat role, Marines also served as security personnel on the ships to which they were assigned, guarding critical areas when enemy boarding actions were deemed likely. Marine units prioritized rapid assaults, leveraging firepower and numerical superiority to overwhelm adversaries, but were prepared to retreat when faced with overwhelming resistance.
During the era of the Galactic Civil War, SpecForce Marines participated in Operation Cobolt, a mission aimed at recovering a Scandoc decoding computer from an orbital base positioned above the planet Mantooine. A Marine unit, utilizing an assault boat, successfully breached the cargo doors of the station after an Infiltrator team neutralized the base's deflector shields. The Marines then established an airlock, facilitating the entry of additional Marines—White Team, Black Team, and Red Team—aboard a Wolden-class shuttle to secure the decoding computer and sabotage the base's power station. With mission objectives achieved, the surviving Marines withdrew, leading to the station's descent into Mantooine's atmosphere. Marines under the command of BL-1707 and Basso were deployed via YM-2800 limpet ship to seize control of an Imperial cargo convoy.
As the Galactic Civil War evolved from an insurgency characterized by hit-and-run tactics, the Marines were increasingly integrated into standard line divisions, working alongside Heavy Weapons Specialists units to lead planetary assaults and landings.

Typically, SpecForce Marines were individuals already adapted to life in space, having either grown up in spaceports and around ships or having spent a considerable portion of their lives in space. They demonstrated an ability to endure the confinement inherent in space travel and living among the stars, and were accustomed to the monotony associated with extended space voyages. Despite their familiarity with ships, Marines generally did not acquire skills such as piloting starships or even astrogation. Given their backgrounds, individuals joining the Alliance were often initially assigned shipboard duties until they requested a transfer to Special Forces, where their experiences led to their induction into the Marines. Following the completion of drop camp, Marines were directly assigned to vessels throughout the Fleet and received on-the-job training. Further training was conducted through drills on moons or in deep space. Training exercises in ship boarding, space combat, and assaults took place in remote locations, such as deep space or isolated planetoids, often utilizing derelict and stripped hulks. Space weapons training was conducted in conjunction with Heavy Weapons Specialists squads.
Life as a Marine was demanding, and the personnel were inherently fighters, possessing resilience, determination, and a reputation for aggressive engagement. While not explicitly stated, other SpecForce personnel often viewed them as somewhat simple-minded, often using the nickname "vacheads." Officially, this nickname was attributed to their operational environment. Marines also gained a reputation for their ferocity in combat, stemming from the extended periods spent aboard ships and in close quarters during their tour of duty. A Marine's primary objectives were straightforward: complete the mission, survive, protect their fellow squad members, and return safely for the next shore leave.
During the Galactic Civil War, Colonel Anena Seertay held the position of Alliance High Command Special Forces Regimental Marine Commander. Seertay was killed in action during the Primtara Offensive. Colonel Anna Seertay led the Marine boarding force that assaulted the Imperial orbital base over Mantooine during Operation Cobolt, while Gideon and Toombs commanded the subsequent Marine assault teams. Both Seertay and Toombs were killed in action during the mission.
Team 19 was a platoon-sized unit stationed aboard the Mon Calamari Star Cruiser Mantan Wanderer, which was part of the 14th Roving Line. Under the leadership of Lieutenant Miko Beski, Team 19 consisted of three Marine squads, a Heavy Weapons Specialists squad, and a squad of Technicians. They served as the primary boarding party force and the core of the planetary assault force.
Marines received training in close-quarters combat, hand-to-hand combat, and engagements in zero-gravity environments. The majority of their training focused on developing and refining the combat skills and tactics essential for fighting aboard starships and other confined structures in space. Technical skills were given secondary importance, while stealth training was kept to a minimum. Marines also had access to the Alliance's limited supply of armored spacesuits and battle suits, and received training in their operation. Marines were capable of identifying which weapons were appropriate for use in specific areas of a ship to prevent unnecessary damage to the vessel during combat operations. They also received training in sabotaging shipboard systems. All Marines were proficient in speaking Galactic Basic Standard.
Marines were experts in combat, trained in the use of blasters and grenades, and skilled in both unarmed combat and melee combat, particularly in zero-gravity conditions. Their survival training emphasized space survival techniques, and they were proficient in administering first aid. In their capacity as shipboard security troops, Marines were trained to operate the weapons systems aboard both capital ships and space transports, and could assist in vessel repairs if necessary. Marines also possessed the ability to bypass security systems.

Marines typically carried light weapons to minimize damage to the interiors of the starships they were operating in, but they did employ heavier weapons when attacking enemy vessels. For protection, Marines wore either a blast vest and blast helmet, or armored spacesuits or battle suits. Marines also favored Karflo Corporation thinsuits due to their versatility. Standard weaponry included blaster pistols, blaster rifles, blaster carbines, grenades—including fragmentation grenades—and a vibroknife. Marines also had access to either a light or medium repeating blaster, although these weapons were generally impractical for use aboard starships, as well as Czerka Arms flame carbines. An encrypted comlink enabled Marines to maintain communication with their unit.
Marine forces were commonly deployed using Katarn-class boarding shuttles or Aegis-class combat shuttles.