Oxy gum ;-)
was his secret of how to breath underwater from what I can remember lol.
& If you were really lucky you could also catch the undersea world of Jacques Cousteau who was on at 7.30 back in the early 70s ,
Some of their diving equipment were very much advanced even in 1971 by today's standards .
Think he was probelly Zodiac inflatables best advert .
http://youtu.be/iuUNVISSpKA