What Is A Vang In Sailing?

A boom vang is a simple device on a sailboat used to control the vertical orientation of the boom and exert downward force on it. It is essential for holding the boom in place when taking down or putting up the sails, as many in-boom furling systems require a specific boom angle. Proper use of a boom vang helps keep the sail full and drawing well.

In its simplest form, a block and tackle are arranged in such a way that it applies downward force to the boom, allowing the sailor to control the tension. The vang allows vertical adjustment of the boom and is an extremely important tool to shape the main for speed. It can be tightened to tighten the leech, flatten the sail, and bend the mast.

A boom vang is the principal tool for controlling twist in the mainsail, which can be a critical part of sail control management. It is usually a hoist attached between the mast foot and the boom, with its variable length determining how high the boom can rise. The vang maintains Vang Power and helps to control mainsail shape after the limits of the traveler have been reached.

Cruisers use the vang to keep the boom from rising when sailing downwind and abraiding the main. The vang is a set of blocks and lines or an adjustable pole used to pull the boom down and shape the sail. When reaching, the vang is the main control which effects mainsail twist.

The boom vang can be a misunderstood sail control, as it takes over the job of pulling down on the boom once the mainsheet is eased. On large cabin cruisers, the vang is only pointed and starts to be used from the transom onwards. On dinghies, the vang is an adjustable line or rope that attaches from the base of the mast to the boom.