The apparent wind comes forward significantly once you get a bit of speed up. If the wind is so strong relative to the boat that it is still that far behind the beam that you are getting lift to lw, you will probably be reefed and the drag will counteract the lw lift.
--- In harryproa@yahoogrou
>
> Mike,
>
> I love getting those long replies of yours. They are always well thought out
> and interesting reading.
>
> One thing that they also tend to do, is to highlight the unspoken
> assumptions I am laboring under. But, before we get to those, I have a very
> basic sail question: How does the airfoil help with downwind (broad reach or
> more) sailing? Perhaps I am just stuck in the old stayed rig mindset, where
> the sail really can't be let out past 45 degrees without the sail chafing
> against the shrouds.
>
> With a rotating, unstayed rig, do you just put the boom out at 90 degrees to
> get lift from a broad reach? Then beyond, up to 135 degrees when running? It
> would seem that the lift vector would then be on the opposite side of the
> boat from the boom (i.e. if the boom was out to starboard, the boat (if a
> monohull) would heel to port). Of course, if the boat really will sail at
> wind speed, then it seems that the speed of the boat will move the apparent
> wind forward of the beam most of the time.
>
> Rob, is that true on the Rare Bird?
>
> Back to my unspoken assumptions. You are correct that I want a boat that I
> can singlehand and that will perform well in light winds (Chesapeake Bay)
> and upwind (beating down through the Bahamas). There are a couple other
> things I also want; large bridgedeck, covered with either a hardtop or
> bimini. To do this, I either need the boom higher than the hardtop, or
> shorter than the distance from the lw hull to the bridgedeck.
>
> I have a layout that I like for everything other than the rig at the moment.
> It comes apart and will fit into a container for shipping (although I am not
> really sure that saves enough over a delivery to make it worth while). In
> order to make that fit, the lw hull can be no more than 4.5' high. Anyway,
> this means that if I use an easyrig, with a 2 part mast, the boom needs to
> be only 7.5 feet long, or 6' in the air (so it doesnt hit the hardtop). I
> could go with a schooner rig, but the masts would still have to be > 39',
> which means they need to be 2 part masts, which sounds expensive? (Did I
> mention that my most important unspoken assumption is that the boat be low
> cost so that I can actually build it??)
>
> Anyway, I am currently at am impasse on this one. I am trying to build a 3D
> model in google sketchup and then I will post the plans and 3D rendering in
> the group to get suggestions. At the end of the day, I am pretty sure I am
> just going to get Rob to do a design of his own, based on my favorite
> layout. His plans always seem to be better than mine, so it will be worth
> the money to me.
>
> Thanks again for the feedback,
>
> - Gardner
> York, PA
>