by lemsteraak » Sun Oct 25, 2015 3:06 pm
SaltyDog,
I would highly recommend rigging a simple vang. I view them primarily as a safety control. Going downwind, the sail will lift your boom, in high winds, your boom can really lift. The problem is that this changes the sail's center of effort and can "control" and turn your boat resulting in an accidental jibe. On a DS it isn't such a big problem because the boat planes and your speed can match the windspeed pretty well. Still, I like to have a vang.
The larger question, how you use a vang to shape your sail, is a lot more complex. Going downwind or on a reach, it does keep the boom down so you spill less air, pretty simple. Going upwind on a DS, I don't use it much. If my mainsheet was connected only mid-boom, it would be another story. In this configuration, you set the vang tight when beating and the mainsheet controls the placement of the boom. In gusts the sail will cause the end of the boom to bend and lift the end allowing the sail's leach to twist off and spill air. This can be a really handy self regulating feature in big waves and winds. The skipper can concentrate more on the course and how best to steer through waves while the main is on auto pilot. In big gusts, you just drop the traveller a tad to spill more air but you never have to touch to mainsheet.