Some folks worry that if the clew grommet were to let go, or if the outhaul were to part, they would have a wildly flogging mainsail, like a genoa without sheets, right over their head. And the boom could drop down if there is no topping lift.What's the alleged advantage of a shelf-footed main over a loose-footed main?
Well, yes, but with extra material that unfolds if the outhaul is eased, thus creating the "shelf." There is also a footed main, which our boat's original main is, which simply has slugs, a bolt-rope or some other attachment mechanism for holding the length of the foot to the boom.That is a fairly standard cruising mainsail arrangement.
The "shelf-foot" refers to a sail foot that is connected to the boom along it's full length.
Proponents of shelf/footed mains will tout the "end plate" effect of the shelf reducing pressure loss around the "loose foot"... Personally I doubt that that effect is significant in the end.
The more uniform shape, easier outhaul loads and ease of bending and unbending the sail that comes with the loose foot (along with simplified reef line rigging, as per SD) come out in its favour for me.
I wouldn't say that that is necessarily true... but you will find that with a new, flatter sail you'll end up reefing later because you'll get more drive/less heeling forces due to it's more efficient shape and adjustablility.So, does that mean that with a loose foot there's less heeling as the wind picks up and thus you don't need to reef as fast?