How does use of the boom vang change on differe...

Michael Varsava

November 10, 2017 “In follow up to your note on the use of the vang. Recognizing that the vang essentially controls the leech when the boom is outside of the traveller, is application of the vang consistently for powering up or does adding vang ever depower the main? Is use of the vang determined by the boat? I have a Laser, an Ultimate 20 and a J/100. The use of the vang seems to differ on each of these boats. Thank you for your input. ”

David Flynn

November 16, 2017 Quantum Expert Answer

The vang can definitely act to depower the mainsail on smaller boats (dinghies) with very flexible masts and no backstay. A Laser is a perfect example. On this type of rig when you pull on the vang hard you are forcing the boom forward at the gooseneck. This forces the mast forward creating mastbend which flattens the mainsail. On a Laser or similar dinghy mast, the standard technique is to pull the vang on hard just before turning upwind if it is windy to flatten and depower the mainsail. The Ultimate 20 would probably fall into this category as well, since it does not have a permanent backstay and has a relatively bendable mast. The J/100 has a backstay so that would be the primary means of creating mastbend to flatten the mainsail.

(If you're interested in learning more, Michael is referring to the recent article: Do I Really Need a Boom Vang?)

The Discussion

Peter Molettiere

Hey David, Can easing the vang also play a roll in depowering the main in very high winds, as well? ie., using twist to spill wind from the top of the sail, where it produces the greatest heeling moment? For example, out boat has a specific vang hydraulic release button right in front of the helm, so the helms-person can ease the vang quickly in a gust… Thanks!