The distribution of noise sources - propulsors and diesels amidships - and the location of receiver spaces directly above presented an interesting problem. The propulsors causes high vibration level and attendant high structure borne noise. The propulsors could not be effectively isolation-mounted due to the waterproof, high-impedance seating required. This precluded source treatments. Thus, the treatment would need to be directed at either the structural path or the receiver acoustic properties