Patent ID: 7047965

Claim:
A swimming snorkel for use by a swimmer while swimming on or adjacent the surface of the water comprising: (a) a mouthpiece; (b) an elongated hollow intake airway having upper and lower ends and communicating between said mouthpiece and air outside said snorkel; (c) a one-way intake valve means in said intake airway for permitting the intake of air and preventing the exhaust of air; (d) an elongated exhaust airway having upper and lower ends and communicating between said mouthpiece and air outside said snorkel; (e) one-way exhaust valve means in said exhaust airway for preventing the intake of air and permitting the exhaust of air; (f) a hollow chamber communicating with said mouthpiece and said lower ends of said intake airway and said exhaust airway and communicating with a purging passage for purging air and water; (g) one-way purge valve means in said purging passage for preventing the intake of air or water and permitting the exhaust of air and water; (h) means for releasably securing said snorkel to the head of said swimmer, whereby said mouthpiece is held in the mouth of said swimmer and said upper ends of said intake airway and said exhaust airway extend above the surface of the water when the head and body of said swimmer are on or adjacent to the surface of the water; wherein said exhaust airway has a cross-sectional area selected to be sufficiently small in at least one section thereof to cause said one-way purge valve to open to release accumulated water when a swimmer exhales with more force than normal, and large enough so that the swimmer can exhale in a normal manner through said exhaust airway while swimming without opening said one-way purge valve means; wherein said cross-sectional area of said exhaust airway in said at least one section thereof is between 0.130 square inch and 0.306 square inch.