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AIR PRESSURE
Operating pressure for the buoyancy tube and the keel is 240mb/3,4 PSI
We recommend the use of a manometer to check the inflation pressure.
Without a pressure gauge, stop inflating when the buoyancy tube is so firm that it is impossible
to bend back the aft cones ends by hand.
It is important to foresee pressure changes: Check and adjust the pressure in the compartments
(by inflating or deflating) when temperature changes occur (especially in tropical areas where
temperature variations are pronounced between morning and night). Be sure that the pressure
doesn’t vary from the recommended zone (220 to 270 mbars).
The temperature of surrounding air and
water will proportionately influence the level
of internal pressure in the buoyancy tube.
Surrounding temperature
Internal pressure in
buoyancy
+1°C
+4 mb / 0.06 PSI
-1°C
-4 mb / 0.06 PSI
RISK OF PRESSURE LOSS
Example: Your boat is on the beach in the sun, temperature 50°C (122°F), at the recommend
pressure (240 mb/3.4 PSI). When you launch the boat into 20°C (68°F) water, the temperature
and the internal pressure in the compartments will both decrease ( as much as 120mb).
Consequently the boat must be topped up to recuperate the loss due to the temperature
difference (between the surrounding air and the water). Also, it’s normal to discover a pressure
loss at the end of the day when outside temperatures decrease.
WARNING
WHEN A BOAT IS UNDER-INFLATED, IT LACKS RIGIDITY IN
NAVIGATION AND WILL PERFORM POORLY. IT ALSO TENDS TO AGE
PREMATURELY.
RISK OF OVER PRESSURE
Example: The boat is inflated to the recommended pressure (240mb/3.4PSI) at the beginning
or end of the day (low outdoor temperature =10°C/50°F). Later in the day, the boat is exposed
to full sunlight (50°C/122°F) either on the beach or on a yacht deck. The temperature inside the
compartments will increase (up to 70°C/158°F) especially with a dark colored buoyancy tube,
causing the pressure to double (480 mb). Deflating is necessary to bring it back to
recommended pressure.
WARNING
IF THE BOAT IS OVER INFLATED, THE EXCESSIVE PRESSURE
EXERTED ON THE INFLATABLE STRUCTURE CAN RUPTURE THE
SEAMS.
