In
Kalymnos, only 18% of the steep
volcanic land could be cultivated, so the main occupations were trading,
boat building and sponge fishing, which perhaps was the oldest occupation on the island. Diving for sponges brought social and economic development to the island: the
freediving method was originally used. Kalymnos was the main centre of sponge production in the
Aegean, and sponge diving is still a traditional albeit less common occupation of the Greeks on the island, with related exhibitions, along with other local folklore, and three museums about the occupation. When sponge diving, the crew went out into the
Mediterranean Sea in a small boat, and used a cylindrical box with a glass bottom to search the sea floor for sponges. When one was found, a diver went overboard to get it. Freediving, he was usually naked and carried a
skandalopetra, a rounded stone tied on a rope to the boat, to take him down to the bottom quickly. The diver then cut the sponge loose from the bottom and put it into a net bag. Depth and bottom time depended on the diver's lung capacity. They often went down about for up to 5 minutes. When the Greek sponge divers started using surface supplied
standard diving suits (locally called
scaphandro) in 1865 the death and injury rate from
decompression sickness was extremely high as the procedures for safe
decompression were as yet unknown. Some estimates put the death toll at around 10,000 Mediterranean divers in the first 50 years of surface supplied diving. French Navy physician
Alfred Le Roy de Mericourt reported that in 1867, the suppliers of the diving suits reported that out of 24 divers using 12 scaphandros, 10 died during the season. By 1868 the Italian doctor Alphonse Gul observed that three divers would share a suit, and of the thirty divers at Kalymnos, two died and two were paralysed that year. The improvement in fatality rate was ascribed to the reduced daily diving time resulting from sharing the suits. ==References==