A few weeks ago I had made a little stainless steel adapter to mount my camera to my kayak for our Placentia Bay trip.
I had just cut a square bar and added the proper holes to get it done quickly to test it out and see how it held up.
The mount worked perfectly so I took some time and made and upgrade with a larger rounded end so that there was more area for the mount to sit on.
And much more ridged.
If anyone wants to do something similar the Valley kayaks come with M6 x 25mm stainless steel bolts. I bought M6 x 30mm SS bolts to replace the factory one and camera mounts are 1/4 20 for your tap size.