Re: Can someone explain roach to me?
A longer boom does two things. One helpful, one harmful.
First it increases sail area, this is good.
Second it reduces aspect ratio, this is bad.
A good designer must balance these things out when designing the rig. As well as a lot of other stuff like: running backs instead of a backstay, mast weight, mast taper, expected loads, boom length and traveler placement, ect...