No, it isn't... At least the manufacturers don't claim that it is....

Couldn't find the word skiff  anywhere on the D-One site, not even in the forums..

Is the D1 hull shape based on that kind of thing? Maybe it is what you get if you cross a skiff with a Finn?

In reply to Roger about the 5o5.

I was writing in the Bethwaite context of the 90's and  he considered the 505 a blow down wind boat.

Just did the current sums, the 5o5 hull weight is 30% greater than the 49er and the righting moment 30% less with also 30% less total down wind sail area. (took both boats beams and SAs from wikipedia and assumed each sailor was 80kg).

Every boat is an apparent wind boat, it's just the extent to which they can exploit the phenomenon that is different.

Out of interest I listened to the JC wordwide podcast with Randy Smythe. Interesting stuff and he relates how he sailed with Dennis Conner in the 1988 America's cup Cat Stars and Stripes. He said that if a ballon was released from the windward mark going dead down wind to the leeward one then the Cat could beat the ballon. I expect that most Cats can now do this. That's real apparent wind sailing.

Could a 49er beat a ballon to the leeward mark? I don't know. Maybe someone here can tell us?
However given the discrepancy between the 49er and 5o5's data and the 5o5 still having a symetrical spinnaker I think it unlikely that even with the new size spinnaker it's still not really an apparent wind boat in the Bethwaite terminology

Originally posted by Riv In reply to Roger about the 5o5. I was writing in the Bethwaite context of the 90's and  he considered the 505 a blow down wind boat. Just did the current sums, the 5o5 hull weight is 30% greater than the 49er and the righting moment 30% less with also 30% less total down wind sail area. (took both boats beams and SAs from wikipedia and assumed each sailor was 80kg). Every boat is an apparent wind boat, it's just the extent to which they can exploit the phenomenon that is different. Out of interest I listened to the JC wordwide podcast with Randy Smythe. Interesting stuff and he relates how he sailed with Dennis Conner in the 1988 America's cup Cat Stars and Stripes. He said that if a ballon was released from the windward mark going dead down wind to the leeward one then the Cat could beat the ballon. I expect that most Cats can now do this. That's real apparent wind sailing. Could a 49er beat a ballon to the leeward mark? I don't know. Maybe someone here can tell us? However given the discrepancy between the 49er and 5o5's data and the 5o5 still having a symetrical spinnaker I think it unlikely that even with the new size spinnaker it's still not really an apparent wind boat in the Bethwaite terminology

Hi Riv
There was a post on another sailing forum last year by Julian Bethwaite which looked at a wide variety of boats as he looked for a path from Oppi to 49er, in response to questions he was always being asked.
Its worth having a read if you haven't already, but here is a nice quote

Finally I have used the ISAF HP definition about sailing faster than the wind, downwind, most of the time, to draw the red line.

Not sure why a 470 dose not do it more often (Tack down wind), but we also know a 29er dose, most of the time, (and yes, I know why a 29er dose).

What is irrefutable is that a 5o5 and to a lesser extent a I14, spend a lot of money and effort setting there boats up so they can quite deliberately switch to HP modes both up-wind and down wind, so, from my POV I consider the 5o5, the tipping point boat, it has has a foot in both camps, one could say the best of both worlds.

If you look it up, (I'm reluctant to put a link here) it's called

Graphic representation of dinghy performance