Here's a PDF I found of the most relevant chapter in Letcher's book: http://www.jesterinfo.org/selfsteeringforsailingcraftjohnletcher/Self-Steeri... After the basics of his experiments & resulting systems he goes into setups for long downwind passages for several pages (twin mains, etc.) - but then in the last few pages he summarizes very well around the basics again, so plow through or skip over the exotic downwind passage rigs and don't miss the summary at the end. cheers, John S. On 11/17/2016 03:26 PM, GILASAILR--- via montgomery_boats wrote: -- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com