A gennaker, but not a genoa
I've checked into this, John, because I'd like more headsail area. Unfortuntely if you look at where the jib sheet blocks are on the deck you'll find that they are too far forward to accommodate anything much bigger. Even with a 110% the sheets would be pulling almost straight down to the deck, stopping you from getting a good, taut sail when beating.The best I can find is a "gennacker", which is like a spinnaker, but with one clew (corner) fastened to the stemhead fitting at the bow, where the jib is fastened. The additional halyard you have running to the top of your mast should be for that.I know that isn't much to go on, but if you do a search for Gennaker on google you'll come up with better explanations.Hope ths helps!Mike