erhan2umi 3 If you wear this with a slipper and walk in the ocean floor (say for more than 3 minutes), it will eventually get a bit of water inside. Short immersions are fine. After you get wet, if you keep your feet out of the water (with the socks on) for sometime in the sun or/and wind; your feet will eventually get dry again. I use it for getting in my kayak from the beach. For this purpose it is sufficient, and much more comfortable than carrying long boots in your kayak. Note that your feet will feel cold if you go out to sea in weather temperatures below 15 degrees Celsius. I gave 3 stars because of the short duration it can hold water out.