WHAT ARE THE DIFFERENT TYPES OF DIVING?
Breath-hold diving (free diving, skin diving). This earliest form of diving is still practiced for both sport and commercial purposes (e.g., ama divers of Japan and Korea and pearl divers of the Tuamoto Archipe-lago). The breath-hold diver’s compressible air spaces are squeezed by the increased water pressure throughout the dive. Each dive, limited by the individual’s tolerance for breath-hold and the risk of drowning from hypoxia, is usually a minute or less. Diving in a heavy-walled vessel. Heavy-walled vessels can maintain their internal atmosphere at or near sea level pressure (‘one atmosphere’), and so prevent the surrounding water pressure from affecting the occupants. Such vessels include: the bathysphere, an unpowered hollow steel ball lowered from the mother ship by steel cable; the bathyscaphe, a bathysphere with buoyancy control so that cable is not needed for descent and ascent; and the submarine, which can travel great distances in any direction under its own power. Diving
