Engine induced sound and vibration levels in commercial and leisure boats is in many cases unacceptably high in terms of passenger comfort and environmental noise. Classical methods of passive treatment are generally less effective due to the low frequency noise content, and often lead to an increase in structural weight. This than contradicts the low weight requirements for increased travel speed. More efficient vibration damping methods must therefore be found. With active engine mounts, it is possible to achieve a decrease in the vibrations even when the hull is not very stiff. This is especially important in marine applications since the engines are mounted on weak and light structures. The AVIIS (Active Vibration Isolation In Ships) project aims at investigating the effects of a combined passive/active engine mount for use in boats. A Storebro 36 Royal Cruiser with two Volvo Penta engines has been used in the project. This paper presents a comparison between a local vibration control at each engine mount contra a more global acoustic control, a ASAC (Active Structure Acoustic Control) approach. The advantage of acoustic control is that only the vibrations that couple strongly to the sound radiated will be attenuated. This also leads to a decrease in power consumption, which is important in a vessel. The calculations are based on real data from the Storebro boat.