XCS Excess15 User Manual page 35

03 RIGGING / SaIlS
03.1 Sailing
BEWARE
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A catamaran is about 6 times more resistant to heeling than a
monohull. In naval architecture, it is referred to as uprighting moment
multiplication of the weight of the boat by the transversal distance
between the centre of gravity and the centre of flotation (or bottom).
See the illustration on the opposite page.
This fact has real consequences as for the sailing and sail trimming
of a catamaran.
The fact that the boat does not heel may mask overcanvassing, which
may be very dangerous for the crew and the boat. Therefore you must
permanently keep a close eye on the speed of the true wind, and trim
the sail surface according to the latter as a matter of priority.
The below-mentioned trims apply in a calm sea. When the sea is
brown, you shall reduce earlier by 10% as far as the speed of true
wind is concerned. And as a general rule, it is absolutely imperative to
permanently try to ease up the boat rather than to stress her.
You will always try to have the forward edges of the sails facing the
apparent wind, and to have the sail not sheeted home, so that the
airflow behind the sail may be laminar, that is to say so that it may go
off the aft part of the sail without any disruption.
In case you shouldn't follow the recommendations, it might be
dangerous for the boat and the crew, and, in case of an accident, the
manufacturer's responsibility would not be involved.
TRIMMING WHEN CLOSE HAULED (between 75 and 50° of wind)
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Wind force given in apparent wind
- From 0 to 5 knots: full sail, mainsail and code 0.
- From 0 to 23 knots: full sail, mainsail and jib.
- From 23 to 28 knots: 1 reef, full jib.
- From 28 to 33 knots: 1 reef, jib 75%.
- From 33 to 38 knots: 2 reefs, jib 60%.
- From 38 to 45 knots: 2 reefs, jib 40%.
- From 45 to 55 knots: 3 reefs only (or try sail, or lying to).
- Over 55 knots: lying to, sea anchor, or preferably scudding.
TRIMMING WHEN DOWN WIND (between 75 and 130° of wind)
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Wind force given in apparent wind
-
From 0 to 16 knots: full sail, mainsail and code 0.
-
From 0 to 20 knots: full sail, mainsail and jib.
- From 20 to 24 knots: 1 reef, full jib.
- From 24 to 30 knots: 2 reefs, jib 75%.
- From 30 to 34 knots: 3 reefs, jib 60%.
- From 34 to 38 knots: 3 reefs, jib 40%.
- From 38 to 50 knots: mainsail lowered, jib 25%.
- Over 50 knots: scudding, depending on the sea, you will set mooring
ropes from one transom extension to the other one in order to reduce
the speed of the boat.
These figures are given for reference only and are to be adapted
regarding external conditions.
WaRNING
If there is a radar aerial on the mast, keep an eye on the jib when you put
about or gybe in order to avoid any risk of damage.
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