How can you breathe using a snorkel while submerged under water ?
Diving with snorkel is mentioned by Aristotle ( 4th century BC ) . “ Just then as divers are sometimes provided with instruments for respiration , through which they can draw air from above the water , and thus may remain for a long time under the sea , so also have elephants been furnished by nature with their lengthened nostril , and , whenever they have to traverse the water , they lift this up above the surface and breathe through it . “ < / ref > The earliest descriptions of frogmen in war are found in Thukydides ' history of the Peloponnesian War .