Scuba dive training and certification agencies

Avoiding skin cuts and grazes

Diving suits also help prevent the diver's skin being damaged by rough or sharp underwater objects, marine animals or coral.

Diving longer and deeper safely

There are a number of techniques to increase the diver's ability to dive deeper and longer:

• technical diving - diving deeper than 40 metres (130 ft) and/or using mixed gases.
• surface supplied diving - use of umbilical gas supply and diving helmets.
• saturation diving - long-term use of underwater habitats under pressure and a gradual release of pressure over several days in a decompression chamber at the end of a dive

Being mobile underwater

The diver needs to be mobile underwater. Streamlining dive gear will reduce drag and improve mobility. Personal mobility is enhanced by swimfins and Diver Propulsion Vehicles. Other equipment to improve mobility includes diving bells and diving shots.

Recreational scuba diving does not have a centralized certifying or regulatory agency, and is mostly self regulated. There are, however, several large diving organizations that train and certify divers and dive instructors, and many diving related sales and rental outlets require proof of diver certification from one of these organizations prior to selling or renting certain diving products or services.

The largest international certification agencies that are currently recognized by most diving outlets for diver certification include:

• American Canadian Underwater Certifications (ACUC) (formerly Association of Canadian Underwater Councils) - originated in Canada in 1969 and expanded internationally in 1984
• British Sub Aqua Club (BSAC) - based in the United Kingdom, mostly for UK divers and clubs
• European Committee of Professional Diving Instructors (CEDIP) based in Europe since 1992 (see Cedip on French Wiki pages)
• Confédération Mondiale des Activités Subaquatiques (CMAS), the World Underwater Federation
• National Association of Underwater Instructors (NAUI) - based in the United States
• Professional Diving Instructors Corporation (PDIC) - based in the United States
• Professional Association of Diving Instructors (PADI) - based in the United States, largest recreational dive training and certification organization in the world
• International Training SDI, TDI & ERDi -based in the United States, TDI is the world's largest technical diving agency, SDI is the recreational division focusing on new methods and online courses, and ERDi is the public safety component.
• Scuba Schools International (SSI) - based in the United States
• YMCA scuba - based in the U.S., part of Young Men's Christian Association (YMCA), a Christian related organization (open to all faiths, ages and genders despite the historic name)