Hi Steve, Yes you can stand on them but it is very awkward. Mine are long and round with a ribbed surface. I have never tried standing on them - I'm not an acrobat, and having a skateboard go out from under me, with me landing on my rump dissuaded me from trying to stand on other round rolly things. As for supporting your weight, it certainly should be more than adequate. A motorboat wake throwing your boat against a pier wall will be a much greater load than just your body weight on a fender. Connie