Noise is the biggest challenge faced by hovercraft designers and builders. In the last year we’ve been conducting a significant project to develop new, more quiet hovercraft, and the Coastal-Pro is the first to benefit from the results.
Much of the credit for this work must go to Keith Oakley. Keith has been involved with hovercraft as a passionate enthusiast for a very long time and over the last few years has tested over 150 hovercraft for their noise signatures. Using the information gained from this, we’ve worked together to improve noise levels using his knowledge together with our experience and engineering facilities. Keith’s work is hugely respected within the hovercraft community – what he wants to achieve is a greater acceptance for hovercraft in both commercial and recreational applications, and to have him working so closely with us to achieve this is a fabulous opportunity for us. Basically (without giving away commercial secrets!) there are about ten significant factors which are responsible for the noise. Some improvements are fairly straightforward and generally understood such as bigger ducts and slower fans. But Keith’s research has also identified some more subtle factors which when addressed as part of an overall design, contribute significant reductions in overall noise levels.
We knew the Coastal-Pro was good but we had only had a chance to run some rough tests. What we were keen to do was to thoroughly test it for ‘flyby’ noise – the most relevant test for a dynamic machine (as opposed to a static test) but had to wait for a calm day without wind to skew the results.
The outcome was extremely satisfying. After averaging three runs, maximum noise at full power measured at 25m was 78dbA. However, at cruising speed (approximately 20 knots) the noise was just 74dbA. This is way down on traditional hovercraft noise levels and we believe it is demonstrably the quietest commercially built hovercraft available anywhere in Europe. In real terms, if you’re standing on a river bank and a Coastal-Pro passes by, the noise simply isn’t unacceptable or offensive.
This is just the first application of the project results to our range of craft, and in some ways the easiest to apply. But our ‘crusade’ continues, and we promise more results in due course. Make sure you ‘like’ our Facebook page and you’ll be the first to hear about them!