Doug,
A review of the building site left me with the understanding that I have not shown the bungee system as well as I could. I have that on pending now and will update it the next building season. Sorry.
What Pete has mentioned is along the same thought process I have had. The longer the bungee line is the less loss of elasticity you will have. The thinking is that the sheets will be at close haul most of the time in a regatta. A super tight bungee then will soon lose its function.
During the refit of 94 last winter 2003, I placed an eye bolt on a piece of basswood glued vertical near the center of the station 45 rib. I put another at the port side of station 27.5 rib. From the collector loop I ran a bungee through a Pekebe block with a hook on it attached at station 45 and hooked the end to station 27.5.
Before I clamped the sleeve on the bungee for the hook at station 27.5, I ran the winch to full sheet out. Then the bungee length was adjusted at the sleeve till there was just a slight droop in the bungee line and clamped it. Now when you close haul the winch you will see that the bungee is not very tight. You will also find that you can easily hook and unhook at both stations in the blind when you need to.
During the season I tied two overhand knots in the bungee line to take up slack. The slack will come early while it is new. I have just finished my winter 2004 maintenance on her and found the bungee in good condition with no need for change as I head east.
If you go to the building site, Building the EC12/Maintenance/Spring Thaw you will see a link to the refit. I have just added a photo (008) that will show those attach points to give an idea where they are. I do not have photos of all of it. You will be able to see that photo Saturday morning as I will upload tonight.
Hope this helps, there is no set length. It is whatever floats your boat...