The Cave Diving Group (CDG) is a United Kingdom-based diver training organization specializing in cave diving. The CDG was founded in 1946 by Graham Balcombe, making it the world's oldest continuing diving club. Graham Balcombe and Jack Sheppard pioneered cave diving in the late 1930s, notably at Wookey Hole in Somerset.
The CDG operates under a federal structure comprising four regionally based sections located in the major caving districts of Britain: Somerset, Welsh, Derbyshire, and Northern, each with its own Secretary, Treasurer, and Training Officer.
The CDG offers a variety of training courses for cave divers, from introductory to advanced levels. The courses cover all aspects of cave diving, from basic skills to team management and rescue. The CDG also publishes a number of books and manuals on cave diving, including the Cave Diving Group Manual, which is considered to be the definitive guide to cave diving in the UK.
The CDG is a non-profit organization and its members are dedicated to the safe exploration of caves. The CDG has a strong safety record and its members have made significant contributions to cave diving research and exploration.
According to the Internet