GM is the abbreviation for which naval rating?

Gunner's Mate is the correct interpretation of the abbreviation GM in the context of naval ratings. This role is integral to the operation and maintenance of various gun systems aboard naval vessels, encompassing both surface ships and submarines. Gunner's Mates are responsible for the installation and repair of weaponry, ammunition, and the handling of various ordnance types, contributing significantly to the vessel's combat readiness.

Understanding this rating is important for grasping naval operations and personnel roles. The other abbreviations presented do not correspond to established ratings or positions within the naval framework, which further reinforces Gunner's Mate as the accurate choice in this scenario.