: Powers lighting, navigation systems, communication tools, and radar.

: Runs hydraulic pumps, air compressors, winches, cranes, and thrusters.

: Ensures bilge water pumps and fire suppression equipment remain active.

An is a secondary power unit designed to handle critical systems and equipment while the main engine is either off or focused solely on propulsion. While primarily associated with the marine industry as "diesel generators" (gensets), auxiliary engines are also used in aircraft (as APUs), heavy trucking, and industrial machinery. Core Functions