GUL is a genuine sports brand. Our 10ATM (100m, 10bar, 330feet) specification means that you can swim, snorkel dive, do watersports, shower etc while wearing your GUL. If you want to do scuba diving, howerer, the watch must be marked 20ATM (200m, 20bar, 660feet). The crown and push buttons should not be manipulated when the watch is immersed. Rinse the watch and strap in fresh water after salt water use.