Stavanger, Sat
Thanks for the sail plans, Antoine.
I am sure both will work. If only we could have had two identical boats, one fitted with the Johanna rig and one with the Fantail rig…
My hunch is that there would not be a radical difference between them in upwind performance. The performance would mainly depend on how much camber the sails get.
Straight downwind I guess the lower AR Fantail sail might be faster, but on the other hand, it would need to be swung forward earlier to off-load the rudder. On none of my boats with Johanna style sails have I needed to do this. On both my last boats, Broremann and Frøken Sørensen, I run out of courage before I run out of rudder, so then I drop a panel or two…
David Thatcher compares his cambered Fantail sail with his former, flat, HM sail and from that experience, he seems to rule out the HM sail. I think that is a bit unfair comparison. When I replaced my Malena’s flat HM sail with a cambered panel HM sail of the same size and AR, it was like having a turbocharger added. That was back in 1994 - it’s only 6 months now to the 20-years anniversary of that blue, cambered panel sail.
So my suggestion, again, is that both sails you have drawn will do fine, and that they will anyway work a lot better than a flat sail. It is more up to you what you like.
Good luck!
Cheers Arne
PS: Btw, the default rake of my masts is vertical, but these sails have proven (to me) that they work with any mast rake from 2 degrees aft to over 5 degrees forward.