A jet transmits significantly less sound into water than a turboprop
PN - not strictly true. It is dependant on engine type and numbers, height above the water and radiation pattern. The MR2 (broadband) was far noisier than the P3 but in a very small directed footprint. Analagous to a spotlight as oppossed to a 60 watt bulb if that makes sense.
Oh for the days of Andros...
