Today's easy question - Vangs

[IanL]

Anyone tried a gnav?
As a way of making light-weather crewing more efficient?

And are they banned, as a similar contrivance? "Prohibitions: Jumper struts, permanently bent masts and booms, rotating masts and other 
similar contrivances."

[John Meadowcroft]

Never seen one on a 12, but dont see why they would not be legal.  It would make a mess of the shape of the lower portion of the sail and the load of the gnav impacting on the mast might make it turn into a funny shape.

[Cookie (Guest)]

I had one on Radical Edward, works fine...

[Lukepiewalker]

I asked a couple of years back and the general opinion was it would do interesting things to the lower mast shape. But ovbiously Mike has actual experience...

[tedcordall]

Most of the ones I've used are pants. The 4000 and 29er have the moveable end of the gnav sliding along the mast or boom and they often barely work unless you put effort into cleaning and siliconing etc.
The one on the RS300 is excellent as it uses large rollers at the mast end.  It also has two rods, one either side of the sail, which allows a more natural sail shape. (unless you fancy the 9er style double sided sail foot - though I have a feeling that this is outside the class rules!)

[tedcordall]

Oh, and I forgot to say (it may be obvious to you, it may not) that with a gnav you can't use a normal gooseneck as the gnav pushes down and back, and as  a result would force the boom off the gooseneck pin as you cranked the kicker on. 
 
Seems like a really good way to make space for the crew, though.