by GreenLake » Mon Aug 03, 2009 5:09 pm
I just read a discussion in another sailing forum, mostly larger boats, where there was pretty strong opinions that loose footed sails are easier to trim for lower wind speeds.
Interestingly, that was also kicked off after someone talked to a sailmaker. Losing the boltrope at the foot would make the sail cheaper, and where there are no class rules, adding a boltrope apparently is sold as a separately priced option.
In theory, having that layer of cloth should have some effect at reducing the flow around the foot of the sail that leads to a vortex that's being shed astern and induces drag. Reducing that flow would reduce drag. (Similar, in effect to the winglets on airplane wings).
Finally, some people claim that for laminated sails, providing the "shelf" at the bottom of the sail is actually tricky, so that could be the reason why loose footed sails are used for some high-end boat.
~ green ~ lake ~ ~