What Is a Cunningham in Sailing?

In sailing, a cunningham or cunningham's eye is a type of downhaul used on a Bermuda rigged sailboat to change the shape of a sail. It is named after its inventor, Briggs Cunningham, a victorious America's Cup skipper and yacht builder.

What is a cunningham and how is it used?

A Cunningham is an adjustment line used to increase the performance of the mainsail by changing its shape. Basically, it is a rope that acts as a downhaul, which is often connected to a cringle in the luff of the mainsail between the tack and first reef point.

What is the purpose of the cunningham?

The cunningham controls the fore and aft position of draft in the mainsail or genoa and works together with the traveler, mainsheet, outhaul and vang to optimize sail shape and increase boatspeed. Cunningham controls lead to the crew to encourage adjustment as wind speed changes.