> gsl, on the van Dusens, at the top of the footstretcher is a tube which runs laterally across the boat. The gunwhale on each side has a horizontal surface. A metal bar running fore and aft is attached to each gunwhale. The tube at the top of the footstretcher is secured between the bars by metal pins which go through holes drilled horizontally through the bars. The upper surface of each bar fastens to the underside of the wing. So that's a close connection which does not run through the hull.
> The lower end of the foot stretcher fastens to the center of the bottom of the footwell.
I also looked at a Hudson single that had the riggers attached to a thin horizontal cantilevered part of the gunwale, which was much thicker and stiffer then the boats I looked at earlier.
So while a bit inconclusive, I'm a long way from convinced that the any flexing of the Van Dusen Advantage or this particular Hudson would cause any speed decrease.
Yes the riggers will be heavier then the two stay design, and the riggers may flex more, but at least for the Van Dusen the flex of the riggers looks to me much less then the oars. I still see the Van Dusen as a good design. Perhaps not optimal but a very good design anyway.
I did talk to an owner of a F-rigger Empacher (bow mounted, non-wing) who said that the Fluid Design forum had long discussions about how to get back into the boat and that few people could do it. She fortunately never had to try in her boat. Given the many reports that bow mounted riggers make getting back into the single difficult and that I've yet to hear anyone say it is not problem, I'm even more convinced bow mounted riggers are a bad idea.