1 The German name given to a tube attachment providing an air supply to a submarine at periscope depth. It was abbreviated in the British Navy as a ‘snort’ and was called a snorkel in the US Navy. A conventional submarine has to use its electric engines after it has dived as its diesel engines depend on a constant supply of oxygen. When the Germans overran the Netherlands in 1940 during the Second World War (1939–45) they captured a half-completed Dutch submarine fitted with a tube which enabled the diesel engines to obtain air so long as the vessel did not go below periscope depth.
2 The name of the breathing tube recreational swimmers use. It allows them to keep their faces under water so that they can view what is below them. See diving.