DEEP DIVING BEGINS

The Greek poet Homer mentions sponge fishermen who dive as deep as 30 metres by holding onto a heavy rock. To compensate for the increasing pressure on their ears, they pour oil into their ear canals and take a mouthful of oil before diving. Once on the bottom, they spit out the oil, cut as many sponges free from the bottom as their breath will allow, and are pulled back to the surface by a tether.