I had an opportunity to get a 4.6 Dualist. It is described as a 'down the line' sail intended for wave riding purist, not very common type of sail here in south west of France as wave windsurf goes along with 40+ kt, more jump than surf I guess, even 3 battens are uncommon. But I wanted to give a try at this two battens very light sail for foiling.
Sailed twice so far with it, first with a descent 15-20kt. I used the sail with a 370 P7 mast (that's what I have) and tuning at recommended specs. It was ok, but not great.
Then I gave a try at very low wind most of the time 10kt with some puff almost reaching 15kt, but that time I used a much softer mast (a goya 310 along a 60cm mast extender, and regular base extention), just a notch less downhaul. The sail is ideally pumpable. I mean, I am not a pumping heroe, I am 50, and definitely not an athlete, but the sail is so light I could really shake the tree, and I got impressive short acceleration in return. Along with a wide 1300 front wing (aeromod freeXL) I could get flying and riding, along a much fitter buddy that used a 7,6 Phantom foil sail (and he did pump). Of course he was faster, but I had fun ducking and carving so easily !

Now I am sure that these kind of sail require some more understanding how to tune correctly.
When not powered, it keeps an odd shape with a vertical crease along the mast. Only when it gets some pressure does it seems to get its profile, though I still think I am not quite correctly tuning it. It does not seems to respond to downhaul tension as my other sails.
I believe mast stiffness (or more likely softness) is key essential.
I'd like to use a goya 340 to rig it, but I don't have the correct extender for this yet (I'll probably make a short base extender to use a 45 mast extender).

My only comparison is an Aerotech Phantom 4.5 wave sail, after only using the Aerotech Freespeed line of sails 9.0-5.8.
The Phantom has a very narrow range of adjustment compared to the Freespeeds, proper outhaul takes a lot more tension, and downhaul I adjust to a crease between the 1st and 2nd baton (from the top), and that is it. When rigged right it pumps really nice, and is very On/Off when sheeting out. I rigged it on a Maui Windsurfing 400 mast and used the adjustable sail top to let out about 10-15 cm of mast. There is a vertical crease in the luff sleeve running along the mast like with your sail, and I was told that is proper by support at Sandy Point Progressive Sports, S. Daytona, Florida, US. I use it for wind starting around 14 knots and up to 30 knots max gust, switching from AFS F770 cm2 wing to S670 cm2 wing around 18 knots.

The Freespeed line stops at 5.0, and from all the advice I got here a 4.5 seemed like a good step down from my 5.8, and it is! Funny thing about the Phantom is if it has too little outhaul it will moan in 25-30 knot gusts, and with too much downhaul it will moan in lower wind speeds, first sail that ever told me when it was not adjusted right

Aerotech is almost never seen here in France. From the site description, I see it figures a dacron luff panel. I suppose it is the same as the dualist : along the mast sleeve, there's a vertical dacron panel. I believe it is part of how that design works to give a specific profile, quite deep and forward when powered, and total flat and neutral when depowered.
I also noticed that the battens on the dualist are in 'S' shape when depowered, but I may have over tightened them.
One other odd with this dualist : the battens angle make rolling the sail very long. I mean when rolled, the resulting package is very long for a 4.6, more like a 6.0 rolled package.

Ever tried a superfreak? they are nearly all dacron and very soft. For foiling I like to keep them pretty flat

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6u1d0 said..
Aerotech is almost never seen here in France. From the site description, I see it figures a dacron luff panel. I suppose it is the same as the dualist : along the mast sleeve, there's a vertical dacron panel. I believe it is part of how that design works to give a specific profile, quite deep and forward when powered, and total flat and neutral when depowered.
I also noticed that the battens on the dualist are in 'S' shape when depowered, but I may have over tightened them.
One other odd with this dualist : the battens angle make rolling the sail very long. I mean when rolled, the resulting package is very long for a 4.6, more like a 6.0 rolled package.

The Aerotech Phantom 4.5 has 5 battens, that may make it better for pumping versus Dualist 2 batten design. Battens should not be S shaped! as far as I know. Try letting out all the batten tension, and then retensioning just until the vertical creases disappear.

Like I said, the Phantom is very touchy about how it is rigged. Can you post a picture of the rigged Dualist?

I've adujusted the battens (released a notch)

The crease along the dacron mast panel. 'Regular' sail setting


General vue, mast unbent.


Mast bent (using weight at mast top and base).


On these pics, I used a 340 goya 85% with a 48 long mast base extention. It turns out I had to make adjustments on the extention as it is reallly badly scalled, so I had to measure it to have accurate setting.
I used it once again yesterday with a more consistent wind (10-20kt). It is great for early take off when underpowered, very light in hand for jibes, but in the gust, I was not so confortable. I added some outhaul tension and it got better, but not great.
It really looks different to my other wave sails, and I think I have to figure out how it reacts to settings adjustments, espacially when some top range is required...

I was looking at the dualist too for a while, but ended up with the dragons. Have you ever tried an S2Maui mast? I used to have a different cc mast in it, but it rigs better with the recommended mast. The S2Maui masts are relatively inexpensive too (compared to competition).

Also keep in mind its not how the sail looks but how it feels on the water which is important. I often find sails with 3 battens already dont really 'look' that nice, with 2 battens there's even less rigid structure to tune out those creases etc.

I know there's some other people using the dualist for foiling, here's one of them, maybe you can send them a pm to ask for settings? www.instagram.com/p/BiIeO50gIj_/?igshid=YmMyMTA2M2Y=

Thanks for the contact WoH, I agree on the looking vs feeling. I try to experiment a lot to get a better understanding of how things work, and rig is really tricky. This sail seems to behave unusually to settings.
For how it feels, I found it great the day I was quite underpowered, as it is terrific to pump, and feels very light all the time, which makes sail flip and carving 'S' so easy. For a flat water rider dreaming of one day waveriding, that's a good ersatz.
Now, it may become my largest sail for sub 15kt days (which means I would give up my over 5m sails, except the one for slalom sailing on cold days).

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6u1d0 said..
Thanks for the contact WoH, I agree on the looking vs feeling. I try to experiment a lot to get a better understanding of how things work, and rig is really tricky. This sail seems to behave unusually to settings.
For how it feels, I found it great the day I was quite underpowered, as it is terrific to pump, and feels very light all the time, which makes sail flip and carving 'S' so easy. For a flat water rider dreaming of one day waveriding, that's a good ersatz.
Now, it may become my largest sail for sub 15kt days (which means I would give up my over 5m sails, except the one for slalom sailing on cold days).

The crease along the luff panel is what my Phantom has and that is correct, as for gusts the Phantom is on/off with sheeting, so when a gust comes I just sheet out and keep on flying. I know that the outhaul takes a lot more pressure than my Freespeed sails. Maybe try more outhaul next time in gusts? Your S2 has a boom setting of 164, are you getting that (maybe measure with a tape), and have you tried 2-3 cm more? The printed specs are not always correct.