Normally, transducers are dry-mounted on the inside of the vessel on the outside of the sea chest or similar to protect box-coolers, suction pipes etc. This means that the ultrasonic signal has to travel from the sea-chest wall to the cooling ribs of the box-cooler. This results in energy loss. Delta-sistems has now developed a completely waterproof transducer with a mounting support that can be placed inside the sea-chest under the box-cooler. Thus, the ultrasonic signal will ‘shine directly’ on the ribs of the box-cooler. The challenge has been to develop a transducer housing that will remain waterproof for years, withstanding its own ultrasonic vibrations. The first prototype of this transducer is now ready, built of POM and stainless steel 316. It now needs to be installed in a sea chest for real-life testing (ref to client participation in research below). Once the first results of this research are in, we shall report about it on our website.