shearwater convert
In August I paddled a Swift Shearwater for four days, and I really liked it with a load of maybe 40 pounds (plus my 225). I paddled one years ago and didn’t like it much – I agreed with rblturtle’s opinion that it was sluggish. This year’s rental, though, was of an infused hull (I can’t remember the name of the layup, but it was shimmery silvery gray). Due to an administrative error earlier in the day we arrived, AO had rented out the two solos we had reserved, so they had to borrow two all-but-new infused demos from the Swift factory next door. Lucky us! I don’t know if it was weight or stiffness or small differences in shape, but the hull was fun to paddle. So there’s one option for you: buy infused.
A second option is to paddle the boat you have, but lock yourself into the boat a little more, for stability. I paddle a Placid Boatworks RapidFire as a kneeling solo, and I do as stevet suggested: a fair amount of the time I have one leg extended forward and one tucked under the seat. However, the Rapid has sea-kayak-style foot braces mounted along the side, so I can lock into a solid support on the side I’m extended on. The knee on the other side is also solid. It’s almost as stable as kneeling on both knees. I don’t know if you could mount that kind of footbrace in the sides of the Merlin II or if you would need a cross-hull footbar, like racers use.
Finally, I have paddled the Wenonah Prism for a few days, and I agree that it is large enough for you. Wenonah would probably outfit it as a kneeling boat for a modest customization charge. It is among my least favorite solos – another one that felt sluggish when I rented one. Maybe one of these days I will score an infused hull for a rental…
Mark
A Deal is in the works!
To all who have given me such a great variety of responses to my question regarding solo canoes similar to “a larger Bell Merlin 2”, be of good cheer! A deal is in the works! I hope to have a new solo within a couple of weeks or so and then paddle it and then post the results in a week or two. So be sure to check back here near the end of October when I will reveal my impressions of the chosen boat … which is a (drum roll) …
wavetrain 
A related observation
I noticed something similar about the Royalex Vagabond I used to own. It wasn’t too maneuverable. Though I can’t heel a canoe to the rail in any sort of confident manner, I’ve found that a “reasonable” amount of heeling will free the stems of a lot of canoes, but that wasn’t true of the Vagabond. Wenonah canoes have straight-line taper between the ends and middle, which is very unlike most other brands which have a rounded taper. Thus, the effective zone of greatest width in the Vagabond is concentrated within a very small area, rather than spread out over a substantial portion of the boat’s length. The reason the stems won’t come free is because with the widest part of the boat concentrated within such a small area, leaning simply causes the widest part of the boat to bury itself deeply in the water. A boat with a more gradual transition from the wide center section to the narrower ends (due to curved taper rather than straight-line taper) does not sink as deeply as a Vagabond when leaned because the same displacement occurs with MUCH less draft. The overall result is that the main thing the Vagabond does well is go straight, and since the Wilderness appears to be an over-sized Vagabond, a heavy person in a Wilderness would likely find the same unresponsiveness to leaning that a small person finds with the Vagabond.
Bell Merlin 2
I regret to report to all that the deal I had in the works did not work out. But the silver lining is that my continuing enjoyment in searching for that next great boat can continue. What a great sport!