I purchased a U.S.Divers Dryview adult full face mask from Walmart to take on a cruise to snorkel in the [REDACTED]. The product was defective and did not allow the CO2 to leave the mask, causing me to pass out while snorkeling in the ocean. I then fully submerged under the water and aspirated sea water. When I regained consciousness I was able to remove the mask are swim to the surface. My lungs were so full of water that I needed to be rescued by life guards and taken to an infirmary on the cruise ship where I was given medication to treat my drowning and remove the water from my lungs. I spent three days in the infirmary and eventually the hospital in [REDACTED] undergoing numerous tests and being treated to remove the water from my lungs. I am an experienced snorkel enthusiast with hundreds of trips snorkeling, a former swimming team member, lifeguard and swimming instructor. I believe a less proficient swimmer would not have survived this defective mask.