Training Agencies
Professional Association of Diving Instructors (PADI)
International Association of Nitrox and Technical Divers (IANTD)
National Association of Cave Divers (NACD)
National Speleogical Society Cave Diving Section (NSS-CDS)
Global Underwater Explorers (GUE)
National Association of Underwater Instructors (NAUI)
Scuba Schools International (SSI)
Young Men's Christian Association (YMCA Scuba)
Confederation Mondiale des Activites Subaquatiques (CMAS)
Diver's Alert Network (DAN)
National Association of Scuba Diving Schools (NASDS)
Professional Scuba Association (PSA)

Cave Diving
Anchialine Caves and Cave Fauna of the World
Woodville Karst Plains Project (WKPP)
Harry Averill's Cave Diving
El Jacinto Pat Expedition Project
Sidemount Passage
Wakulla2 (USDCT)

Wreck Diving
Captain J.T.'s East Coast Wreck Diving
The Wreck Page
Bjorn Jensen's Vertical Wreck
Florida Wreck Database
Northeast Scotland Wreck Divers
North Carolina Wreck Diving
Andrea Doria (NJ Scuba)

Equipment and Dive Theory
Jim Cobb's Trimix Page
Hogarthian Gear Configuration - J. Jablonski
Oxygen Hacker's Companion
Diving Physics and "Fizzyology" - R. Pyle
Importance of Deep Stops - R. Pyle
Cave Rig - T. Leonard
Physiology and Medical Aspects of Scuba Diving
Dive Rite
Halcyon
Extreme Exposure