Hi Wouter,
I don't think that the rig is the major contributing factor to a monos upwind performace, or lack of..... Just don't think they are as efficient as a cat in using the boat's weight as righting momentum. The only way I see they can minimise the disadvantage is by using wings (skiffs) or canting keel (yachts). Please read what I wrote previously and add your thoughts.
Dont forget that a monos weight without crew is balanced over the keel line and with crew, its righting momentom is the weight of only its crew. In an 18s case, it is 3 crew 7.5 feet from the center line. 15 foot wing span I believe now.
A cats righing momentum is the weight of the platform and its rig from the windward side of the leeward board...... plus the crews weight, 8 foot (or just under 10 foot for a T) out from the pivot point.
Looking at this, the cat has a lot more righing momentum and uses the weight of the boat far more efficiently.
As for skiff rig tension, I believe that the reason for the high rig tension is to give the rig enough prebend to support a mast head kite without inverting the rig, whilst using a lighter / smaller mast section.
It also allows a bit more gust response than a stiffer wing mast. A mono does not harness and transfer the energy from a gust as well as a cat, but tends to transfer it more to heel, thus the need for better gust response.
Sorry T_E, but if monos were to maximise their efficiecy, they will have to strap on another hull or 2......... or hydrofoils <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />
