I looked at the available ballast bags, but couldn't find any that were long enough. The other problem would be that they are round. I didn't know this would be a problem when I made my bag and just happened to make it a "flat bag." It lays on the FB deck about 20 inches wide and three or four inches thick when filled. No air. I can watch the water glug back and forth (actually, it doesn't glug because no air. It is amazingly silent).
My wife thought that the roll bag increased the boat's fore and aft pitching. Nope, but when now encountering a wake from the side, the most noticiable effect is the fore/aft pitching as we go over the wake. It's not increased. It's just that without the slamming from side-to-side the fore/aft pitch is what gets noticed. I'll take that noticeable rocking horse ride over the previous bell ringing, coffee spilling side roll. Which brings me back to the commercially available round ballast bags. After one of our open crossings I went up to the FB and found that my "flat" bag had rolled over. There was enough fore/aft pitching to move it. A round bag would definately have to be strapped in place. Probably a good idea for my flat bag, but I think I'll modify it first.
Unlike stabilizers and fins, the ART damping effect takes place at a different time in the roll. With stabilizers and fins, when the vessel is momentarily paused at the maximum roll, there is no stabilization effect. Both paravanes are doing nothing because there is no force on them (other than the always present drag from moving forward). Fins are also doing nothing at this point. As the vessel rolls back towards center, that movement results in force applied to the paravane/fin by the water trying to move past them. I'm not sure when the most force is applied to the paravane or fin, but I would think toward the center of the vessel's "pendulum" movement. In an ART that is timed right, the water sloshes to the low side a fraction of a second after maximum roll. So the full stabilizing force is applied earlier in the roll. Interesting to find out whether the "timing" of an anti-roll force reduces the amount of force neccessary to stabilize. It sure seems like 25 gallons of moving water wouldn't have the amount of effect it has.
Came back south around Cape Caution today but, darn it, it was glassy smooth with no swell, no chop, no wind. Didn't get any further testing in. Did get cell phone coverage. Also, it was so smooth I stopped and caught a nice ling cod.