photo of the white pvc tube between the gooseneck and rotation arm
photo of bungee and pulleys/blocks and line. Photo is a bit bright, but see the two blocks right in line with the shroud? Bungee is run continuous from bridle tang to bridle tang (1/4" dia. or larger). I put a caribeener between the two blocks so we could (easily) unhook the positive rotation after racing, and leave it set up for the next day.
BTW, that's the best crew in the world, my son Paul!
Check through the hundreds of photos here for other views. There's lots of variations of how each individual rigs their boat and some people don't use the positive rotation.
Sheet In...Max Out
sailflatlands at gmail dot com