During the Summer:
For stand-up paddle boarding in the summer, you should wear neoprene clothes that keep you warm, even when wet, and protect you against friction against the board. They will prevent the “freezing” effect caused by the evaporation of water on the skin due to the wind.
You can combine a neoprene tank top and shorts, or opt for shortjohns (braces and shorts) or longjohns (braces and long legs). Neoprene clothes allow for freedom of arm movement that makes it easier to handle your paddle.
If you cast off from rocks, remember to wear neoprene wetsuit slippers to protect your feet.
During The Spring and Fall:
In mid-season, it is impossible to go touring on a stand-up paddle board in a boardshort. You need some basic equipment in case if you fall in the water. You can be easily exposed to the cold, wind and rain.
You need to adapt your clothing to the way you go stand-up paddle boarding. For SUP surfing, you need a neoprene surfing wetsuit, because you will frequently fall into the water. For SUP touring, opt for neoprene longjohns that will keep you warm even when wet, plus a light jacket to protect yourself against the wind and splashing water.
If you go SUP racing on calm waters, wear your running gear, to evacuate your perspiration when paddling hard
I also wear neoprene slippers that are resistant to abrasion and keep me warm.