There is certainly no rule that a SUP paddle boarder should wear water sport shoes or go barefoot. It’s totally up to your choice and the conditions you’re planning to paddle in.
In some areas like rivers, bays and shallow parts of the ocean, the ground may hide lots of sharp rocks, oyster shells or other objects. Consequently, your feet will touch the uncomfortable ground so water sport shoes is a good suggestion.
During the chilly winter when the cold water constantly washing over the board along with the freezing air, your feet will go numb. In this case, you will likely want the right type of shoes to add warmth and insulation. Besides, wearing waterproof shoes or socks can keep your feet dry and warm when launching in the areas where your feet may get wet but not be totally submerged.
When it gets warmer, some people tend to go barefoot to use their toes for balance and keeping themselves upright. The closer connection with the board movements supports the players quickly get in or get out the water if necessary. Bare feet also bring greater confidence and more security for shifts in a stance or for tricks on the board. Many flat water paddlers and yoga enthusiasts prefer going barefoot rather than wearing neoprene shoes or booties.
The features for standard SUP shoes is the same for all categories:
Be made of quick-drying materials. Shoes that absorb water will hinder your movements.
Contain good drainage and ventilation to allow water to flow out.
Support quick shifting and gripping the board with the feet.