by GreenLake » Tue Oct 15, 2013 10:13 pm
Bob, I don't race under class rules, but where I do sail in races we have rather extreme traffic, and collision windows can be a valuable safety feature that I would not want to see restricted. I also don't think that they should be mandated. I assume your question is based on the concern that someone could try to turn the whole sail into a "window" and essentially going to laminated sails by a back door.
I further assume that small windows for 'telltales" are not a problem since the way they affect performance would be primarily by letting you observe the telltales not because of their aerodynamics.
However, looking at the larger windows your photo, I would say that any large windows that are placed higher, or extend higher than the ones shown on the windward boat would no longer qualify as "collision" windows, since they would only be useful for that purpose at ridiculous angles of heel.
I can't speak to the rationale that caused DS 13164 to sport such a large window in their jib, but if I had one, I would get used to it quickly and loath to give it up.
I would be interested to find out whether DS 13156 and DS 13164 are shown during trials to determine whether the larger windows give a performance edge. If they did, and I was racing against DS 13164, then I would probably not mind upgrading my sails, because I would justify the added expense with the increased safety, and benefit from that on crowed waters even when I'm not racing.
But, because I never see another DS to race against here, my views are just my very personal take.
~ green ~ lake ~ ~