8/20
AIR PRESSURE
NOTE
Before checking the boat’s air pressure, turn all I/C valves to the
"INFLATION POSITION" (“red area”). at 12 o’clock,
Operating pressure for the buoyancy tube and the keel is 240 Mbar / 3.4 PSI (+/- 5%)
Operating pressure for the H2P is 1100 mbar / 15.95 PSI (+/- 20%)
How to foresee pressure changes: Check and adjust the pressure in the compartments (by
inflating or deflating) when noticeable temperature changes occur, especially in tropical areas where
important temperature variations occur between morning and night. Make sure the pressure doesn’t
vary from the recommended boat operating pressure parameters of 240mbar = 3.4PSI +/- 10%
The ambient or water temperature will alter
the main buoyancy tube pressure by 4 mbar
or 0.06PSI for every degree Celsius, or
1.8°Farenheit variation as shown here:
1 bar = 1000 millibars = 14.50 PSI
240mbar x 0.01450 = 3.48 = 3.4 PSI
Ambient
or water temperature
Internal
buoyancy tube pressure
Plus 1°C or 1.8°F
Plus 4 mbar or 0.06 PSI
Minus 1°C or 1.8°F
Minus 4 mbar or 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 mbar). 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 110mbar). Consequently the
boat must be topped up to recuperate the pressure loss, due to the temperature difference (between
the ambient air and the water). By the same token, it’s normal to discover a pressure loss at the end of
the day when outside temperatures decrease.
IN CASE OF UNDER PRESSURE OR UNDER INFLATION
Top the boat up to its recommended pressure.
Turn all I/C valve flywheels to the inflation position, (red area) at 12 o’clock.
Unscrew both butterfly wing nuts on the lower buoyancy tubes.
Unscrew any valve cap, and place the pressure gauge in that valve insert.
Unscrew the valve cap on the valve opposite the pressure gauge.
Insert the foot pump hose into that valve.
Inflate to adjust the pressure, while monitoring the pressure gauge on the other side of the
buoyancy tube, until correct and desired pressure is reached.
Turn all I/C valves to the “navigation” position (“green area”) at 6 o’clock.
Screw back the valve caps on both valves. The one with the pressure gauge and the one you
were pumping air into the boat.
Tighten the butterfly wing nuts on the lower buoyancy tubes.
Return the pressure gauge to the repair kit, where it should be, and return the repair kit to one of
the boat’s pouches, as it always should be with the boat. (Same as the foot pump and hose).
Always take both with you, on your sorties.
WARNING
WHEN UNDER-INFLATED, THE BOAT WILL LACK RIGIDITY IN
NAVIGATION, WILL PERFORM POORLY AND AGE PREMATURELY.
