6. The Snorkel Dry Snorkel - There is only one 100% dry snorkel on the market, the Oceanic Ultra-Dry Snorkel. It has a patented self regulating valve that senses the difference in weight between air and water, so the snorkel top "shuts off" when submerged and automatically "opens up" when you surface. It is a fail safe and time tested device that allows a diver the benefit from never having to clear a snorkel of water when it is in use. This snorkel is guaranteed to be 100% dry Semi Dry Snorkel - At the top of the snorkel, many manufacturers offer a "deflector" type device that discourages water from entering the snorkel. Purge Snorkel - These snorkels allow ease of clearing the snorkel of water. There is a one way valve at the bottom of the snorkel, so less air is used to clear it.