Well, like I said, probably the best thing would be to paddle a boat that I know I thought was stable before, but that isn’t going to be easy, for reasons I won’t go into here.
I paddled a Wenonah Voyageur (17’ 6" solo) for four days on Lake Powell, but a loaded boat is far more stable than unloaded. When I’d take it out for a practice paddle, before the trip, I usually put a seven gallon water jug behind the seat.
I made some modifications to the SOT today. I took off the seat and foot braces, which were just in my way. I may try gluing some closed cell blocks on the side to give my legs something to brace against. Next time I’ll also add something heavy to the cargo area.
I’m even thinking of putting an inflatable pool in the backyard to practice my balance.
I just sold the same model kayak last month. I let four individuals try it - no one liked it. It was faster than the sit ins, but the newbies found it unnerving (tippy?, but nobody tipped over) My son and I simply found it to be uncomfortable. The couple that I sold it to were buying it for their children who would be jumping in and out of it on a lake.
I was on a group hike, a couple days ago, and one of the women on the hike happened to have a sit on top that she loves to paddle.
The first time she got on it, she tipped over. But she feels very confident on it now.
I told her about the Pelican I bought and she seemed to think Pelicans were great boats.
I still think the problem may be that I’m only contacting the boat in two places. My rear end and my feet. My legs don’t touch the boat. I can’t stabilize myself in the boat.
I’m going to try and fix that and see if that fixes the “problem”.
Here’s the thing, it’s not like I’ve never been in a kayak before. I owned a tiny little Walden, that I paddled around the res a few times, and felt stable in that. I had a Swift sea kayak, that I paddled around Lake Powell, which has big houseboats that make some pretty good sized waves, and had no problem with stability in that. I’ve been paddling for years and I’ve never tipped over a boat.
So it’s either this boat or I’m just really, really rusty. I was trying to think what was the last time I did any serious paddling and I think it’s been 16 or 17 years.
Has your upper body weight changed much over the 16-17 years?
I have also been away from paddling for a number of years and gained some weight and lost some flexibility. I don’t think the stability of the average canoe has changed much, but where I once could have easily stood up in still water now it is imposable or close to it.
She mentioned the same thing about SOT when I showed her she said she liked her thighs against the pads in a Sit In as well as her feet on the foot rests. I think a Sit In you are also closer to the water line. 
I could be as much as ten pounds heavier, but probably more like fiver or six.
Significant, but it’s not like I gained fifty pounds or anything.
I think it’s a combination of factors.
Boat may have less primary stability than I’m used to.
No knee or thigh contact with boat, so I can’t stabilize myself.
I’ve had shoulder, elbow and heart surgery since I paddled last, so I’m less confident than I used to be.
I haven’t paddled for a long time, so I’m rusty.
All these together add up to getting freaked out the first time I tried this boat.
I tried different sit ins when a local store took a bunch down to the bay. One looked great but was it ever tippy. I did try some sots and they seemed stable. I had been used to a Pelican from the big C. Wanted something with better tracking. I looked at the Ascends, they seem like a good fishing yak but are a bit heavy. I stuck with a sit in…warmer in cooler weather. I was worried the hull design wasn’t the w, I was used to, but it only took me a minute to love the new boat. If you aren’t comfortable now then it’s not for you.
Over the weekend we took her out in her new OT Trip 10 for the first time. she couldn’t believe how stable it felt compared to the cheaper lighter capacity sit ins she had been using. I was impressed how good it was tracking as it was a pretty windy day and my canoe was having issues.
For the OP you will just have to give it a few more tries and make some mods if you can so you can brace your knees or thighs better, Maybe a seat change would help something holding you side to side a bit.
I’m waiting for a block of mini cell, some glue and a seat pad from NRS.
When it gets here, I’ll start cutting, shaping and glueing.
If it comes out looking somewhat professional, I’ll post a photo.
I need to have it ready by June 2 for a canoe club outing.
Im surprised to hear people use thigh braces on a SOT. My only SOT experience is limited to surfskis which are usually tippier than rec kayaks, but no braces are used. The Triangle of stability is Butt, Feet, Paddle. Thighs should have no contact with the boat unless its at the bottom of the leg drive motion.
Are regular SOT’s different because they’re wider?
Also, I think its safe to say if you havent paddled much in 16 years, you’ve lost most of the muscle memory and just need to re-train. I notice a decline in balance after 6 weeks, so 16 years is definitely enough to press the ‘hard reset’ button of stability. That’s why this boat seems tippy. Just paddle 3x a week and after a month it will feel as stable as a dock.
Feet are hooked into a ski no?
Thigh straps for SOTs are great in the surf and rapids. Pretty much useless on flat water unless you are a very aggressive paddler.
technically yes, there is a foot strap, but the only time I have ever needed it was on one particular day that is in my top 5 biggest days ever paddled - 10’ swell with 2’ wind waves, 30+ kt wind. The wind waves boosted me onto a huge groundswell that was stacking up in the rip created outside the breakwall. Open water the swell was 10’ and was stacking higher and steeper by the rip. I was flying down the face of a larger than 10 foot swell at 14 mph (per GPS) and was bouncing over the 1-2’ wind waves so violently I actually wondered if I could be thrown out of the boat or open water pitchpole.
Other than that the foot strap is just something the help carry the boat or hold onto while I remount. It does nothing for stability (for me at least, and that seems to be the general consensus of the ski community)
Surf and WW makes perfect sense
I have a 16ft Hobie Revo that if I haven’t used in a while feels ridiculously tippy, to the point that I don’t feel safe on flat calm water at all. Typically I paddle long narrow sea kayaks and I feel perfectly stable in them. For me it is just the center of gravity change. Going to the Hobie I feel like I am sitting up a foot above where I would normally be and it feels totally wrong and unstable… however, if I use the Hobie for a while I adjust and then it magically becomes the most stable boat in the world and I am taking it out on the ocean in relatively big waves. I don’t know how much you have paddled your SOT but I know it takes me maybe four to five good outings before I am comfortable on it again… I am also old and top heavy so that doesn’t help 
That looks like it would work, all right. I used dry wall sanding screen. NRS used to call it dragon skin.
I finished my outfitting. I bought 4" thick minicell and it was too thick for my band saw so I didn’t do as much sculpting as I’d planned. But I glued what I made onto the boat and I just sat in it and looks like it might work, if it doesn’t come off.
I also stuck a Padz kayak seat pad in place, to replace the seat I took out.
I’m not going to get it in the water till the club outing in a few days.
I ordered a six liter dromedary bag to put in the cargo area, but looks like it won’t get here in time. I’ll have to use several water bottles instead.