Quote:
Originally Posted by Par Four
I've been laboring under the non-sailors misperception that max speed of a sailing craft would be limited to the speed of the wind. Never thought any more about it.
But check me out to see if I now "get it" as result of watching the replay of Sunday's rce. I may invent some of my own words and concepts here, but humor me.
A sailboats speed is a complex relationship of multiple variables. Some primary variables are hull design and hydrodynamic efficiency, sail size and configuration/ shape, and apparent wind speed.
These foil equipped sailboats are able to reduce their hydro drag to minimal amounts, once the boat speed gets up past a crossover point of lift from the foils / weight of the boat.
I presume that cats do somewhat the same when they're able to lift one side out of the water, reducing drag, increasing the peed potential of the "lift" provided by the sail area, in relationship to the wind.
So with these foil racing boats, speed (obviously) can and does exceed the apparent wind speed due to minimal drag, and... The huge amount of sail area which give big time lift or pulling power in relation to the weight of the craft.
So the more efficient your hydro, the more efficient you sail geometry, etc, etc ad the better tactical sailer... The fast better you go.
Something like that?
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Pretty much like that. The only thing I would modify in your description is
Sail Area. In todays boats The BIG factor is
Sail Shape rather than area. In this case (AC72s) the Mainsail is actually an "articulated" Wing..very much like the wing of an airplane which can be adjusted.
When the boat is Put Up for the night..the entire "Rig".. Wing Mast, has to be removed from the boat with a crane because the Sail can't be lowered as in "Ordinary" sailboats. The Jib is a conventional "soft sail" and can..as seen in the video, be lowered.
NB