I haven't seen anything inflatable near sturgeon waters before. The initial problem I see with anchoring a pontoon is getting the anchor point dead center. I can imagine a rather nasty surprise should you try to anchor off center.
With the kayak, I have a trolley that runs up and down the side of my kayak. I thread the anchor through a loop on the trolley which becomes my anchor point. That anchor point is then completely adjustable from the bow to the stern
That is rather important when the Willamette's flows are down and there's a wind pushing from the north. Often times my anchor point will be towards the front of the kayak, and I'll end up river of the anchor.
At times like that, I can get away with a 3.5# folding anchor and less than 150' of rope.
But this time of year things change drasticly. The river is a moving, and I even gave up fishing on xmas-eve because it was flowing too high for me to feel comfortable when I was on the hook. I was using an 8# river mushroom and had about 350' of dacron out to hold me.
Ideally you should be anchoring with an ideal anchor scope of 3-5:1 Sometimes more if needed. Where I've been fishing most the this season, I've been in 75' of water. That would equal at least 225' of rope. you'll see I had a lot more of that a few weeks ago, and I still wasn't feeling too good about anchoring.
Anchoring takes a good amount of practice, and I don't think it's gonna be a good time of year to practice...