The concept of snorkeling goes back some 5,000 years ago, and may have originated in Crete where ocean farmers used hollowed-out reeds to enable breathing while engaged in the gathering of sea sponges. Certainly the practice was known by the ancient Greeks in the Common Era: Aristotle writes of divers using “instruments for respiration” that resembled elephants’ trunks. Leonardo da Vinci is credited with the invention of the first modern snorkel in the 16th century. In the quest for a rig that would be more maneuverable for underwater exploration than the diving bell— invented by Alexander the Great around 300BC and improved upon in successive centuries—da Vinci created a contraption whereby a hollow tube would be attached to a diver's leather helmet. Da Vinci also designed a self-contained diving suit and webbed swimming gloves similar to those worn by SCUBA divers today.
To learn more about ancient and modern scuba technology, clickie the links:
Scuba Adventures Key West: Early History of Snorkeling