Doonesbury by Garry Trudeau for April 26, 1972
Zonker: As an early riser walks along the beach, he spots a few bubbles far out to sea....what can it be breaking the still water of the early morn? A crowd of people quickly forms! As a lone snorkle rises up from the sea, a mighty hue and cry are heard form the people! "Who is that brave man?," they wonder! C'est moi, Zonker cousteau!