Oyster News 49 - Oyster Yachts

FACT BOX
As with any sail, regular inspection of
the sail for chafe and general
wear and tear will be of benefit in the
long run, and reduce repair bills.
Particular attention should be paid to
batten pockets where they may
touch spreaders or shrouds. Chafe
protection patches should be applied
in the area of the spreaders. Carry
spares in your sail repair kit.
Pay particular attention when folding
away mainsails ensuring battens lie
flat, not twisted, and the sail is curled
rather than creased along edges.
Annual washing removes salt and dirt
which work their way into the
fibres of the sail and cause damage.
After use ease the halyard, outhaul
and batten pocket tensions,
particularly if they have been heavily
tensioned.
Always cover your mainsail with the
sail cover after use, particularly in
areas of extended sun exposure.
RECOMMENDED READING
Easy reading: Looking at Sail,
Bruce Banks and Dick Kenny
Medium reading: The Art and
Science of Sail Making, Tom Whidden
Reference book level: The Aero/
Hydrodynamics of Sailing,
Tony Marchjai
Other interesting reading:
Sail Power, Wallace Ross
More to do with racing but
nonetheless an interesting insight:
Winning in One Designs:
Robert Hopkins
28 www.oystermarine.com
REEFING
If the main is constantly
backwinding and perhaps even
wiping out (totally backwinding
from luff to leach), it is time to
consider reefing. Most boats will
benefit from reducing headsail size
first. Either set a reduced foot
length sail or roll some headsail
away. Once the headsail has been
reduced to the point where the
clew has reached the mast and
wind conditions are still too strong,
then look to reef the mainsail.
Generally it is best to try and match
the leach profiles of the main and
headsails (see Article 1 - Headsails).
If you have moved the headsail
sheeting car back a little to open up
the genoa leach in slightly over
pressed conditions, you should try
to match the leach profile of the
mainsail. You can achieve this by
twisting the main leach by easing
the sheet or vang a little.
Additionally if the headsail is eased
then the main should be eased.
WINDWARD SAILING MODES
When sailing to windward, you
should try to decide which mode
you wish to sail in. There are two
Good comparison of high traveller and closed
leach with eased traveller and more open leach
modes. Mode one when sailing close to the wind is referred to as high pointing mode. Mode two,
which is still sailing close to the wind but slightly further away from it, is called footing mode. You
can judge which mode by watching the mainsail's upper leach telltales.
When high pointing (mode one), is desirable, the upper leach telltales should be stalling about
50% of the time. This means, having applied more leach tension through the sheet and or vang,
the telltales should disappear behind the main about 50% of the time. High pointing is excellent
to make a weather mark or keep above another yacht’s dirty air.
When footing (mode two) the upper leach telltales always stream aft. This is achieved by reducing
tension on the sheet and or vang. Incidentally this is how the main should always be set when
sailing off wind. Footing is slightly quicker and is best used when you know you are going to lay
the mark or you believe there will be an imminent wind shift.
The overall difference in speed between high pointing and footing is approximately 10% of your
overall boat speed. Whilst you may seek to adopt one of the modes, by necessity you often find
you are working between the two.
An appreciation of why you may want to be in either mode generates a better feel for sail trim.
It also helps bring an awareness of where you would like to be on the course both strategically
(your position relative to the conditions) and tactically (your position relative to the other boats).
In the next issue we will be looking at the art of offwind sailing with reference to spinnaker and
cruising chute setting and trimming.