LeeD said..
The LONG mast helps stability.
The fuze and wings don't help at all and contribute to dead weight at the end of a long lever.

You are entitled to your own opinions, but not your own laws of physics.

The inertial mass moment (of any foil setup) is orders of magnitude above that of an 8" wave fin. It also increases with the square of the radius from the rotational centre - so even short increases in mast length can result in a large increase in the moment of inertia.

I sold my original surf foil last June, and had to wait for the Armstrong 1850 to arrive a month later. During this period, I purchased 8 inch FCS long board fins, and slapped them in the foil boxes of my 6'0" F-One Rocket (120 L). I figured I'd try SUPing until the new foil arrived. Talk about unstable. For wing specific boards, they tend to be smaller and boxier than regular SUP's, so there is a lot more pitch and roll. Wing boards also tend to be lighter in weight, as the point of their design is easier lift (less weight). To make a long story short, it didn't work well so I borrowed my buddies 7.5 ft SUP until the foil arrived.

I'm definitely not from oz nor highly skilled in SUP or SUP foiling. My background is mainly short board surfing and some prone foiling. I've dabbled enough in SUP foil to know it has its own challenges.
Regarding your question about paddling the SUP foil, There are a few on this forum that SUP foil 95 liter boards 6 ft in length, They aren't lightweights either. Guys like Dave from Bundenburg who weighs 85 kg, blow me away by how easy he makes it look. So it can be done.

SUP with foil attached is more stable than similar sized SUP with fins attached full stop.
When I went from SUP to foil I found myself still able to stay out in the surf when the wind picked up to 15 knots + in swirly waters caused by current, rebounding surface chop & swell from a breakwall.
The guys on SUPs did their usual complaints & left me on my own dealing with those increasing forces that I was getting quite used to. Id be out there for another hour. Even the short boarders left just after the SUPs not long after.
So I've experienced it many a time.
But! Muscle memory also plays an important part. I now do SUP and foil mixed. So going from one to the other I definitely feel the imbalance on both within the first 10 minutes. So judging the difference needs a good half hour. And I would guarantee more falls without the foil attached.
Obviously the foil acts like a keel that slows the side to side & forward & back swaying due to the surface areas of all foil components.

LeeD, I think you are making a major mistake: the weight of the foil is totally negligible, first because the actual weight is nearly nothing once you add Archimedes forces, (a floating foil like the Go Foil will have a ... negative weight in your analogy) and second because the dynamic forces of the water on the foil surface (wing, mast and stab) are orders of magnitude greater than the weight.

And... the water forces act just as much on all the surfaces, be it wing, mast stab. And even more on the wing as it is farther from the center of rotation (the board) than the mast, and thus has more leverage.

Colas.........the mast provides surface area to help resist rocking motion as the rails dip one or the other.
The much heavier wing just adds momentum to the rocking force, because the wing has no surface area when it is rocked by unstable legs, rail to eail.

LeeD said..
Colas.........the mast provides surface area to help resist rocking motion as the rails dip one or the other.
The much heavier wing just adds momentum to the rocking force, because the wing has no surface area when it is rocked by unstable legs, rail to eail.

Just a drawing to make you understand the basic geometry:

Look at the board from the rear or front:
rolling on the side moves the mast AND the wing (red arrows), with a movement component of the wing that is orthogonal to the wing surface area (green arrow).

And most foils wings are LIGHTER than water!

LeeD said..
The foil does not give stability.
The MAST give stability, while a weight, up to 8 lbs., adds momentum when you rock rail to rail.

I have to think you are not serious and just trying to get a reaction. Ok, it worked on me.

Now stop with the silliness

Why does this thread remind me of the recent US election

Took the advice of the group and went out with my foil attached for some practice.
A lot more stable than I thought it would be and happy with the results.
Need to get out and practice my J strokes and turns now but looking forward to learning the new skills.

Thanks for your advice.

Yo Lee. Your flawed perception does not trump physics.

I've paddled all three scenarios with a heavy aluminum mast and fuse.

Want me to explain what you felt? Underwater currents acting on your foil. That's the feeling you ascribing to the swing. Physics is not an opinion and perception is not fact.

but why do you and why do I care? I don't know know. i just got sick of saying one has done this. I paddled my my foil SUP on snorkel one day and used the mast as a fin. Regretted it. It was not half as stable as with the foil.

I've done it and I understand high school physics. Chill. By now the original poster has done both too but is too scared to post his results lol.

Good luck. Regarding what was said earlier about feeling water movement on the foil. I remember getting my new foil and paddling out on days where it wasn't the right condition. It was a new toy and wanted to just try it. Anyway, lots of water moving around that day on the inside. It surprised my by how different the board/foil was to paddle relative to the day before. Strong side currents can really mess up stability.