So, in the summer when it is warm I like to run barefoot in the sand at the sea. More complicated so come fall and winter unless u like your toes to turn blue :-) Hence, my purchase of the Primus Swimrun boots. As with all of my Vivoes (is that the correct plural form of Vivo?) these Swimruns are great to run in. They are a little difficult to put on due to the collar at the ankle. But the collar at the ankle serves a purpose - they help to keep water out and more importantly, the sand from the beach. Go Vivo!