It certainly looks like a lot of upper body work. In video 2, the sailor is really sawing that mainsheet (with one hand). What approximate speed would you say that moth was going?

The winds look on the light side, and the water is pretty flat. How do they fare in the heavier stuff?

Andinista,

As a fellow engineer, maybe you will like the kind of information about foils available at Tom Speer's website.

If you want to search the web, the following multihull series are foilers:

Hobie Trifoiler (small trimaran, L shaped foils)
Windrider Rave (small trimaran, T shaped foils)
Catri line (cabin trimaran, Bruce foils mainly)

You may also like the site of the International Hydrofoils Society.

And perhaps you will be interested in the only South American shipyard building hydrofoil boats - Multicascos, in Maceió, Brazil. The first Catri 27 is mine.

You may write to them in English o en tu idioma (los dueños son Argentinos), ou em Portugues, porque eles vivem no Brasil há décadas.

Sds.
Luiz Schechter

Thanks Luiz, great information. Muchas gracias, supongo que eres de Brasil?

Soy Brasileño de Rio y mi educación fue en Portugues, pero no tengo inconveniente en usar el Castellano, ya que hoy vivo en Asunción y mi esposa es de acá.

Con cual bote navegas?

Saludos,
Luiz

Im guessing 12 knots. The videos are sailing across melville water. My home water..
The waves in that area rarely get much bigger than twice that size. The wind however is generally twice the strength what you see. So the moth sailors are used to sailing in 25 knot and greater wind strengths. Here at least they dont have huge seas to content with . Other localities in the state do.

I would suggest all current foiled moths are based on standard moth hulls. The videos look like Growler hulls but I may be mistaken. These boats have a foiled plate and rudder fitted. Although many Aussie moth skippers may rip out a hull during the winter.

Mary, the choices of wings is almost personal. The reason for the fabric panel makes it easier to slide out and more comfortable in non hiking conditions. I havent seen a solid wing in years (too heavy many hulls are between 7 and 10 Kgs)
Hope this helps
Stewart

Doesn't help. By "solid," I was referring to the weave of the fabric on the wings. Some of the wings are a densely woven fabric, while others are a very open netting, and other wings have no covering at all. As you said, the choice is obviously personal; but on a development boat like the Moth, I'm sure the "personal" choice is related more to speed and efficiency than to comfort. That's why I asked about the advantages and disadvantages of each.

Mary,
I will ask the mothies tomorrow. I do doubt that anyone has done any real tests on air drag/resistance.

a few thoughts based on observations not experience.

Having ropes slip thru the open webbing panels and potentially catching, may be an issue. I dont know but there isnt much room on a moth. Nor much stability and things happen fast. So anything that reduces the time to react will end with a swim. A main that sticks will see you swimming at least every second go-about. A kicker rope that doesnt release is a swim at the top mark.

Secondly comfort is important. As the videos show the moth is a huge workout. Fatigue is a real issue. A fatigue means a slow responce which means swim.

I know, from one sail on a slim skiff moth (yes really really experienced ), that even experienced skiff sailors will swim a few times on the way to the start line. It was a a 1km away. Thats my excuse and Im sticking to it.

Stewart

This is a tangent, but what's the rationale for wings rather than trapezing (or wings+trapezing) on these boats? Do class rules prevent it?

Mark.

There was olso this T.
Look at this side,
http://home-1.tiscali.nl/~hbsmits/hydrpic.htm

There is a preview of a DVD that was produced from the Moth worlds a few weeks ago. http://www.moth-sailing.org/dvd/order.html

A fair number of those pictures are taken directly / also apprear in "Icarus: The Boat That Flies", John Grogano


Interestinly, this boat



is incorrectly titled, it is not "Longbow", but "Blue Arrow", which was not a flying boat at all.

Blue Arrow used foils to support a single centre hull (boat needed float tanks when it was not moving or it would just fall over !)

Leaward foil was set to provide lift and windward foil was set to provide downforce and both foils stayed in the water to provide stability. THis boat looked like it was going to totally "change the Rules" of how radical boats migh be designed in the future, however the boat broke up before entering any serious races and the sponsers did not have the time/money or commitment (not sure which) to continue.

More food for thought,
As if cat sailors need another adjustment.
http://www.i14.org/boat/articles/bieker-rudder.html