I've sailed my ACA rig a few times with the tack of the sail right up against the mast (I have hole drilled in the fore end of the boom which accpets a collar with a pin brazed onto it).....I suppose that, configured like, that it's tantamount to some sort of gunter, given that the yard, plumb, extends a fair bit higher than the mast. It's certainly not designed to be sailed like this that seemed to sail well with the luff essentially vertical. Left the leeboard thwart and did not seem to impact helm balance much at all. I just bought a brand new ACA rig...if by chance you're wanting a used one in good shape, def DM me as I doubt it's appropriate to discuss here. All best, David