Mainsail question: Monohull vs Multihull

[fhrussell]

Why is it you never see a mainsail on a multihull where the clew is lower (closer to the deck) than the tack, like you see on many monohulls (like a
J/24)?

http://www.dandwboatworks.com/Mini4.GIF

http://www.jboats.com/j24/j24dimensions.htm

[gonzo]

Many of the odd shapes in sails are for beating a measuring rule, not for overall efficiency.

[Petros]

I could hazard a guess; on production monohulls the intent is comfort and apparent deck room, a low clew reduces visibility from the cockpit and crowds the deck (less head room). Multi-hulls are always performance oriented, so they are trying to get as much sail area as possible. I have built monohull dinghys with a relatively high boom and and a loose footed sail that was tied off at the base of the mast to get more sail area.

You can see both types on either hulls depending on the design intent, performance oriented monohulls will have similar rig features as seen on mulithulls, with less concession to comfort.

[HakimKlunker]

Don't remember where exactly I once read it (it was a book about beach cats):
The Vortex is less when the clew sits higher and a sail is more efficient at higher speeds. There will be a more scientific explanation to say the same, of course.

In my eyes this also counts for monos, but with much tension on the vang, lots of mast curve and rake - the clew has no other chance than to come low.

[Doug Lord]

Originally Posted by fhrussell

Why is it you never see a mainsail on a multihull where the clew is lower (closer to the deck) than the tack, like you see on many monohulls (like a
J/24)?

http://www.dandwboatworks.com/Mini4.GIF

http://www.jboats.com/j24/j24dimensions.htm

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Well, the venerable Hobie 16 is one where you do:

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