ABSTRACT
There is little agreement on most aspects of technical diving, and even its definition attracts controversy. In its widest usage it is diving outside the normal range of air diving. For this chapter it is considered to include diving with any gas mixture other than air, with decompression in the water. Some would also note that it is largely an amateur-organized approach to diving. This is only partly correct as most of the methods come from, and are used by, professional organizations. Others would not include oxygen/nitrogen mixture (nitrox) diving in the definition.
