The Oday 25 is masthead rigged with a stiff mast. Most of my experience in the last 30 years has been with performance type boats with "bendy" rigs and backstay adjusters. I've got no illusions on the performance capabilities of the Oday and my racing days are long over but on the other hand I just can't sit and sail and not fiddle with the trim. I guess I'm answering my original question and I'll setup a flattening reef anyway.
I couldn't find a lot info online so what I'd like to know is: what does a flattening reef do? Is it only for depowering the main before a full reef is needed?
Rich
If the sail has a cringle a few inches above the Clew it was designed for a flattening reef.
What it does is beat rating rules. The rule says the sail cannot be adjusted past a band on the boom. This is the "E" measurement rating rules use for area. If you ease the out haul to put camber in the sail (increase draft) the foot will be short of the band and the sail cannot have full area and full draft.
With a flattening reef, the idea was to use the full rated foot length and get full draft. Then to reduce draft the flattener is put in to pull the clew out to the band. The sail stays within the marks and has full area over a wider range of draft adjustments. The flattener also raises the boom a few inches so to keep it out of the water on a power reach.
Modern sails don't stretch anywhere near as much as those when flattening reefs were all the rage. You might think that you can do away with the flattener and just pull the out haul out farther, but that does not put the loads on the sail in the same place as the flattener and the shape will not be as good.
You have a bit of racing history in that sail. If the cloth and shape are still good you may as well rig it the way it was designed.
Randy
