Sailing with a Cunningham

In an earlier post I highlighted that the Topper Xenon has a cunningham in oppose to a downhaul. This is not just another rope and is extremely useful when racing and of course sailing in general.  If you have a Xenon you have got to learn how to use it. In our last race the Barman and I noticed a significant improvement.

The cunningham adjusts the tension in the luff extremely quickly and easily. By hauling it in or easing the line, the tension in the luff can be changed, thereby shifting the point of maximum draft forward or aft so as to optimize the sail shape.

I have found the greatest impact is when you are trying to point upwind on a close haul. If the cunningham tension is on, you don't point very high.

This bit from the Xenon manual starts to now make a bit more sense....

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.

Topper Xenon's Cunningham not Downhaul

Sailing parlance can be very confusing at times as the same thing onboard can be called a number of different names (e.g. a kicker, boom vang, gnav, thingme giggy etc). When learning to sail this doesn't help your speedy understanding of the technicalities of sail setting. Another example is the downhaul; on the Topper Xenon which is called a cunningham!

The cunningham differs from a typical downhaul in the way that it attaches to the sail. The system usually consists of a line which is secured at one end to the mast or boom below the foot of the mainsail. It is then passed through a cringle in the luff of the sail near the foot, but above the tack, and then led down on the other side to a fitting on the mast or boom or on deck.

It is named after its inventor, Briggs Swift Cunningham II, a victorious America Cup skipper, who was a yacht builder and sailor, as well as being a racecar enthusiast, driver, team owner, and racecar owner and builder. The yacht, Columbia, was led to victory by Cunningham in the America Cup competition of 1958. Briggs was inducted into the America Cup Hall of Fame in 1993. He is also in the international and American motorsports halls of fame and when innovating devices for yachting, called on the specialized talents of automobile racing friends to solve problems such as metal stress and selection.

There you go!