boom vang installation

[thedavo]

I have found myself uneasy with the prospect of sailing off the wind without a vang. Especially dead downwind.  The boom is so long on a CP27 that I am concerned that it may catch the backstay on crash gybe taking out the backstay. I have been searching for the the formula to determine where the boom attachment goes in relation to the deck-to-gooseneck height. I found it once, but have not been able to since. Any input on how far aft the boom attachment goes? Thanks. Dave.

[Steve W.]

I seem to recall that it should be 1 to 1 or 45 degree (boom 3.5 feet from foot, vang att point 3.5 feet from mast)

[thedavo]

Steve, went with your formula. 42" aft of the gooseneck works like a champ. Thanks a bunch. Dave.