A snorkel has an inhalation tube and a check valve near a mouthpiece which allows air to flow toward the mouthpiece, and a float valve which closes the inhalation tube. An exhalation tube has a second check valve also located near the mouthpiece which only allows air to flow into the exhalation tube. The snorkel has a purge valve positioned below the mouthpiece. A further check valve is positioned between the inhalation tube and the exhalation tube to allow air or water in the exhalation tube to pass to the inhalation tube placed as close to the first check valve as possible. The exhalation tube outlet orifice may be closed by a simple gravity actuated valve which will float open during a dive. Alternatively the exhalation tube outlet orifice may be closed by a float valve.