https://starwars.fandom.com/wiki/Coastal_defender_stormtrooper

Coastal defender stormtroopers, more commonly known as shoretroopers, with those stationed on the planet Scarif referred to as Scarif stormtroopers, were a specialized variant of the Galactic Empire's stormtroopers trained and equipped for combat in tropical environments. Shoretroopers operated effectively as sergeants, allowing them to command small squads of regular stormtroopers. One of the notable aspects of coastal defender stormtroopers was that the position they served in was temporary and subject to change along with their rank. On a galactic scale, shoretroopers were scarce, as the conditions for necessitating their employment were few and far between, as few stations or garrisons were located on coastal/tropical planets.