A split-trash compacting system for a vessel having a plurality of compartments comprising a trash compacting assembly disposed in a first compartment of the vessel readily accessible to persons on the vessel for receiving and compacting trash. The service module permits servicing and repair of a marine vessel without removal from the water. The actuation mechanism comprises at least a main arm 31, a front auxiliary arm 32 and a rear auxiliary arm 33, the main arm 31 being articulated on the front auxiliary arm 32 and being mounted on the rear auxiliary arm 33 by a cam follower that cooperates with a slot 312.