The ancient Greeks and Turks have been called the “Fathers of Modern Diving.” As they dove for sponges in the Aegean Sea more than 2,000 years ago, they learned many techniques which are still useful to divers today.
These ancient divers realized that the more air a diver took down underwater with him, the longer he could stay underwater. One diver, no one knows exactly who, thought of a way of carrying extra air down with him in a bag type of device called a water bladder. This water bladder was made from the skin of a goat, sheep, or pig.
The bag was oiled to make it waterproof, then all but one small opening was sewn up tightly. While still on the surface, the diver blew the skin full of air. Then he tied a heavy stone around his waist to keep him underwater, and he dove down. As he worked on the ocean floor, he took sips of air from the inflated skin as he needed it.
The sponges these ancient people dove for, while they are attached to the ocean floor and look like plants, are actually animals, with the remarkable power to grow back any parts of their bodies which are broken off!