Besides glare reflected by the water around, the harmful UV is also a great consideration in choosing kayaking sunglasses. So your kayaking sunglasses should have the function of blocking glare as well as UV. The head strap that prevents your sunglasses from dropping is also important. To withstand the force of wave, the frame and lenses should be strong. Moreover, lenses with hydrophobic outer coating are preferable. Here is the a website where you can find economical and professional kayaking sunglasses: https://seaspecs.com/
If you want to buy the sunglasses for kayaking, you could just go to choose the ray ban polarized sunglasses which will shield your eyes from the glares on water surface. You could choose the one with good quality. There are of course other brands of the sunglasses. The ray ban series are with good reputation. You could choose that one.
To some degree, selecting a tint is a key matter. However, certain tints offer advantages for specific visual tasks and environments. If 100 percent accuracy in color perception, a neutral gray tint is the best choice. But to enhance contrast, brown and copper-colored tints are often best. Depending on lighting conditions, yellow, amber, orange and red tints also are good choices for contrast enhancement. So I suggest you to choose brown or copper-colored one.