I do not keep my thighs locked into thigh braces. Unless, of course, I have some kayak design where the fit forces the issue. I find this interferes with stroke mechanics on a level I find frustrating, even navigating rough water that is pushing the boat around. For someone who says “flexibility and balance were always terrible”, and just based upon the discussion of how different kayaks have felt to CA139, my bet is that if thighs are locked in, and a kayak does a natural slight tilt to the left, the right knee would strongly engage to hold the body from tipping over the the left. This is a natural engrained reaction. Most capsizes I see, the person is engaging their right leg against the top of the boat to tip them over to the left, or engaging their left leg against the top of the boat to tip them over to the right. At the same time, if they were to simply relax that leg, and drop it down to the bottom of the hull, they wouldn’t have tipped over. In other words, you watch them pull the hull upside down trying to brace against the top of the boat.
Things have to become pretty rough before you’re required to engage your left leg against the top of the boat to keep from tipping to the left. Why would it be counterintuitive to engage your left leg against the top of the boat to keep from tipping to the left. CA139, try sitting at a desk or table where there is a minimal clearance between the tops of your legs and the bottom of the table or desk. Drop a pencil or pen or book a little distance out on your left. Now lean to the left and pick the item up off of the floor. I bet you don’t give the slightest thought towards engaging your right knee against the solid desk or table to stabilize yourself. It’s engrained muscle memory. In a kayak, you’re sitting in a boat with a solid deck. Your right knee will want to brace against that solid deck to stabilize you from tipping over to the left. We’re not used to sitting on something solid that can spin 360 degrees. We’re land mammals. It’s not natural.
This is what you’re up against in terms of reprogramming your balance when in a kayak, or any boat. I don’t know if being stiffer and more unbalanced in general makes the transition tougher, but for anyone, stupid-repetitive boat-balance practice can eat up the learning curve in a hurry. As you’re probably aware, if you’re thinking about capsizing and balance at all while you paddle, you will feel like you’re working harder, and you will be overall, but your speed will decrease. Attacking the forward stroke hoping balance will come is one way to go, and probably most common. I think it would be worth a try for you to attack balance straight away, and I think you’ll see more leaps and bounds forward with your forward stroke proficiency using that approach.
I haven’t been in the Volan, but it’s very likely to fall into the fairly stable sea kayak category, which seems may be outside of your abilities at the moment. I would put you in something with really high secondary stability, as it makes learning boat balance more forgiving. You’ll have a split second to realize you are pulling your boat over on top of yourself, and have that moment to react by relaxing your leg that’s pulling you over.
But you’re right, it doesn’t take much to max out the speed of shorter boats. You’ve gotten lessons and lots of seat time, so my best suggestion is trying an approach that you haven’t focused on before, as it seems apparent you haven’t had that boat balance epiphany yet.