Here is some useful information for me and my crew to remember when sailing the Zambezi Shark (aka Topper Xenon) - particularly the Barman, as we were definitely rusty during Friday evening's pursuit race er....or was it just me??
The aim this course is of course to beat those pesky Lasers. BTW everything below comes from the Topper manual so must be true..
Upwind
For a medium wind (crew sitting out hard, but able to sheet the mainsail to the centreline) you should be able to use maximum power. Use very little or no cunningham. The outhaul should be set so that there is about a 3in (7-8cm) gap between mainsail foot and boom at the point of maximum chord. Try to keep the boom on the centreline, provided that the boat remains flat.
The jib can be eased about 1-2in (5-10cm) from maximum tightness for optimum performance. As the wind increases, reduce the power in the mainsail by pulling down on the cunningham progressively until the boat feels comfortable and balanced again. If you have tell tales on the leech, use enough gnav to keep them flying.
For very windy conditions flatten the main by tightening the outhaul, tensioning the cunningham further (with a fully-battened sail this has the effect of flattening the sail without pulling the fullness forward and can therefore be used much more than with a conventional mainsail). Sit out hard and sail free.
In light airs, use little or no gnav to allow the leech to open.
Tacking
Be aware that with a fully-battened sail the power comes on very fast after the tack. Do not over steer with the rudder as you will find yourself on a reach. Do not sheet in hard immediately, with either main or jib, until the boat has picked up speed after the tack. Whenever the boat slows down it pays to ease sheets, bear off a couple of degrees and then oint up again once the boat has regained speed. In light winds, when about to tack, make sure that there is some gnav tension, as this will help the battens to flick across. Ease the sheet a few inches before tacking. A sharp pull when you reach the new tack will also help the battens across.
Downwind
With an asymmetric Spinnaker, large distances can be gained (and lost!) very quickly. It is essential to keep the boat traveling at the optimum speed and direction towards the next mark. This direction will vary according to the wind strength. In light airs, at displacement speeds, where sailing higher will not result in a great increase in speed, it pays to sail low towards the mark. In marginal planing conditions, sailing higher will allow the boat to plane and the consequent increase in speed help to offset the extra distance traveled. The boat can be sailed progressively lower as the wind strength increases.
Just when to sail high or low and at what precise angles will come only with experience, so keep practicing. The crew can have a better idea of the correct angle to sail by feeling the power in the spinnaker sheet. Allow the crew to call the pressure. Sail as low as possible, keeping the pressure on, unless there are overriding tactical considerations.
Gybing
An asymmetric Spinnaker is far easier to gybe than a conventional spinnaker and takes no longer than tacking. Ideally you should always gybe when the boat is traveling at maximum speed as there is less pressure on the sails. It therefore pays to gybe 'reachto- run'.
If you try to slow down and gybe 'run-to-run' the spinnaker pulls the top of the mast forward, making the boat unstable and less controllable. The additional air pressure will make the mainsail harder to pull across. So be positive and gybe smoothly and at speed.
In strong winds you will probably have borne off so that, although the apparent wind still shows a broad reach, you are in fact running directly before the true wind. If you then try to gybe through your normal angle you will gybe on to a reach and be overpowered! So in strong conditions remember to gybe through a smaller angle. As with tacking, apply some gnav tension and Cunningham when gybing in light airs to help the battens flick across.
