HOVERCRAFT AND THE ENVIRONMENT
The hovercraft was invented in 1956 when air was being tested as a lubricant to reduce the drag
arising from the motion of a boats hull passing through the water, and as a result, the world's
most environmentally friendly motorised vessel was created. For most people a hovercraft is a
new experience, and knowledge of them usually comes from newspapers, television, magazines
and the like, and consequently misconceptions are rife. Recreational hovercraft ride about 25 cms
high on a bubble or cushion of air, enabling these craft to travel even over environmentally
sensitive areas without disturbing the surface.
Hovercraft travel on a low-pressure cushion of air with the hull well clear of the surface, hence there is
no bow wave or wash to damage the shoreline or disturb marine life.
Because there are no underwater protrusions in a hovercraft;
- the fatal strike to a turtle or dugong (or any other marine creature) associated with a
conventional propeller driven craft is impossible,
- the below water thrashing noise of a conventional propeller does not exist,
- sea-bed erosion when operating in shallow waters is eliminated.
Hovercraft do not need any damaging modification to the environment for their use.
i.e. concrete boat ramps, dredged channels, channel markers, jetties, piers etc.
Fuel systems on a hovercraft are fully contained within the hull structure and any accidental
discharges or leaks are contained within the craft and cannot enter the water or
contaminate the environment.
With no part of the hull in the water, toxic anti-fouling paints are not required to
keep the hovercraft hull clean of various marine growths.
The low-pressure air cushion below a hovercraft reduces drag to almost zero,
cutting fuel consumption to about half that required for a similar sized conventional
craft resulting in considerably less atmospheric pollution.
A unique charactistic of hovercraft that gives it the ability to make virtually no impact
on sandy beaches or intertidal flats is it's extremely low "footprint pressure".
i.e. an average human standing on a beach exerts a pressure of around 20 kPa
under foot, rising to 172 kPa when walking. By comparison, a recreational
hovercraft exerts a pressure of around 2.2 kPa on the surface regardless of the
speed. This "footprint pressure" is lower than normal daily atmospheric variations,
or less than that of a seagull standing on one leg.
Hovercraft have been successfully used for weed control on many drinking water
storage dams throughout Australia.
The modern four stroke powered private recreational hovercraft has a very low
atmospheric sound signature, approximately the same as an average similar sized
powerboat. Outboards, Jet ski's, motorbikes and small aircraft have all put a lot of
effort into reducing noise in recent years, and recreational hovercraft are no