Harken 40mm Carbo ratchet block with becket HK2609 to the middelseat and a standard block to the boom.

Did not try it yet, but i'm ready to sail....

Ruud

   (mine is a dory, but same principle?)  

Harken ratchet block mid boom lashed to boom.  Sheet thru simple block on end of boom, to the ratchet, and loose end to sailor, with no cleat for the sheet.  I got a ratchet block with a switch to turn the ratchet feature on or off, but it works so well I never turn it off.  In this picture I stil had the original non ratchet block on the boom, to first prove in the ratchet...it works great so I took the original one off.  

PS:  Some builders have concerns about cleating off the main sheet in boats as sensitive as ours so the ratchet block is a good compromise to make it easier on the hands.

Curt

https://picasaweb.google.com/114717787929554738224/BuildingWoodenBoatCLCNortheasterDory?authkey=Gv1sRgCKCBzczm_aKs2wE&feat=directlink#6064878447249988466

   Here is a thread you may be interested in:

http://www.clcboats.com/forum/clcforum/thread/28655.html

 Ratchet block to the boom seems a good idea to me. However i  replaced the camcleated block (because the cleat was to eager to get the rope) 

Thanks guys

These were very helpful

John