This program proves the validity of a multi-spectral exhaust system concept for surface ships. The preliminary designs considering signature, weight, cost, and environmental impacts on the retrofit of existing ships with these systems were developed in Phase I. Specimen panels were tested to determine acoustic, thermal, visual, and radar performance. Phase II will: Provide a detail design of a concept for the LMU 1500; Modify the hot test facility at the Naval Surface Warfare Center, Carderock Division, Annapolis, MD to simulate the flow conditions of the LMU 1500; Fabricate a full scale two duct segment of the design; Fabricate an evaluation suppressor for the LMU 1500 and support its installation for Naval Evaluation on a Navy Research Vessel.