This is a replacement paddle button for the Intex K1 Challenger Kayak. It may work on other kayaks that use the same or similar design.
Would recommend printing vertically so that you have the button as circular as possible. I tried printing on its side and it didn't fit well however that could give better shear strength if your printer can print with better quality.
Paddle spring button assembly
Injection molded button to be replaced
Molded vs Printed
When I got our new Intex K1 Challenger Kayak, I lost one of the buttons that hold the paddle together. Rather than sticking with my ink pen and stick solution I figured I'd design and print a new one. The part is designed in Solidworks.
Be careful when removing the little spring button assembly as the spring is pretty strong and can shoot the button into your face (and get lost in the woods as I found out).