14/20
GENERAL INFORMATION (CON’T)
Second Example: When temperatures rise:
Date
Time
Pressure Temp
Jan 01
16:00
240 mbar 20°C
Jan 02
16:00
210 mbar 25°C
Difference
24hrs
30 mbar + 5°C x 4 = -20 (when pressure rises: subtract!)
Result
210 mbar
-20
= 190 mbar
Corrected Pressure = 240 mbar – 190 = 50 mbar: boat failed test!
When the temperature rises, you subtract the amount of the corrected temperature to the
amount of your pressure difference.
Third Example: When temperatures are constant:
The difference between the beginning and the end of the test will be subtracted, and that
figure will be your actual or true pressure loss.
NOTE
In the first two examples above, the corrected pressure drop is not at all
what one would have expected. The first one shows a pressure drop of 30
mbar, when in actuality the corrected pressure loss is 10 mbar, as for the
second example, what looks like an acceptable pressure loss of –30 really
is a unacceptable one of -50 mbar! This is why it is of primary importance to
do corrected pressure loss tests and not simple pressure loss tests.
TOWING:
Never use the bow-carrying handle, use the 2 D-rings on each side of the bow, and attach a towing
sling.
For best performance while towing, cross towing lines, port to starboard and starboard to port, thus
describing an "X" with your towing line.
LIFTING:
When hoisting a boat with a lifting sling, use the 2 D300 lifting rings on top of the buoyancy tubes
in the bow, and the 2 transom eyebolts.
Do not hoist boat with personnel on board,
Only use a certified lifting sling and check its SWL (Safe Working Load) with the manufacturer of
the lifting sling.
Inspect all your lifting appliances regularly at least every 12 months, or better still, have it done by a
professional.
