- "Yeah -- That's why he ordered us Sea-Commandos to launch boarding parties!"
- ―Unidentified New Republic Sea Commando
Several years before the return of Emperor Palpatine, the Empire researched a possible gravity well generator in the Sedri system. The soldiers who participated in the operation made use of special equipment which allowed them to function at all depths beneath the oceans of Sedri. When the Rebel Alliance first landed on the planet, it was the native Sedrians who gave them them training and valuable experience in the art of aquatic warfare. This allowed the Rebels to sneak on board the Imperial garrison base and examine the Imperial equipment. Based on this knowledge and discussions with the Sedrians, the Sea Commandos were born.
After the formation of the New Republic, the Sea Commandos were adopted as part of their military. In 10 ABY Sea Commando teams were present at the Battle of Calamari where they boarded World Devastators attacking the planet Dac.
Sea Commandos were constantly shipped from world to world to broaden their experience and produce reliable soldiers the New Republic could turn to for any duty in an aquatic environment. They were trained in all manner of water environment; from moving through bogs and bayous to climbing up waterfalls and cataracts. Equipment typically carried by Sea Commandos included blaster rifles, concussion grenades, stun grenades, grapple guns, blast helmets, blast armor, waterproof uniforms, and survival kits.
- Dark Empire (First appearance)