■What small is the noise level of the Jetfoil?

While the Jetfoil sails in FOILBORNE operation, the noise level in the passenger cabin is 65~80db(A), almost the same level as that of a jet plane. So, conversation in the passenger cabin is not disturbed. The following table shows the examples of the noise level.

On the other hand, the noise level at ten meters (10m) away from the Jetfoil with gas turbines at maximum power is 90~100db(A).
The noise level comes down during port operation with gas turbines at low power.

Normal conversation 60dB(A)
Quiet park 30dB(A)
Quiet room 40dB(A)
Office 50dB(A)
Quiet street 60dB(A)
Subway 80dB(A)
Shinkansen (Bullet train)
(20m distance from a bullet train rail)
75dB(A)
Under railway bridge 90dB(A)


■What is the life of the Jetfoil?

The first Jetfoil which was built by The Boeing Company in 1975 is still in service between Hong Kong and Macau.
For the conventional ship, they have corrosion on the hull, their engine performance goes down during long service and then the operation of them becomes not economical. Consequently they are forced to go out of service.


Jetfoil Boat No.1 "FLORES"

On the other hand, for the Jetfoil, the hull is made of aluminum alloy which is anti-corrosive material and her engines are periodically overhauled to recover its original performance ( called OVERHAUL NEW ), hence the Jetfoil does not suffer deterioration in economy and performance even in long period of service.


■Fuel consumption of the Jetfoil

When the Jetfoil cruises at 43knots FOILBORNE speed, the gas turbine fuel (gas oil) consumption rate is approximately 2,150 l/h. This is not small comparing the diesel engine ships, instead, a lot of merits like light weight, high power, high speed and low vibration can be obtained by the use of gas turbines. It might be considered rather inexpensive in a sense. Talking about the fuel consumption, it is necessary to consider the cruising distance per hour. The consumption per cruising distance, namely a necessary fuel quantity for a certain cruising distance of the Jetfoil is quite same as the one of the diesel engine driven high speed ship such as SWATH type ship.