| ACUC | American Canadian Underwater Certifications, Canada Formed in 1969. | acuc.es |
| ANDI | American Nitrox Divers International, USA Specialise in training programs for technical diving and closed circuit rebreather systems. | andihq.com |
| BSAC | British Sub Aqua Club The BSAC is the governing body for the sport of scuba diving in the UK. It is a club-based organisation that offers training for members through a branch, or intensive courses through a BSAC school. BSAC was established in 1953 by Oscar Gugen. | bsac.com |
| CMAS | Confédération Mondiale des Activités Subaquatiques World Underwater Federation of Underwater Activities. Established 1959. | cmas.org |
| DIVEIAC | DIVEIAC | diveiac.com |
| DRI | Dive Rescue International | diverescueintl.com |
| FIAS | La Federazione Italiana Attività Subacquee | fias.it |
| FLASSA | Fédération Luxembourgeoise des Activités et Sports Subaquatiques, Luxemburg. | flassa.lu |
| HAS | INTERNATIONAL (Handicapped scuba Assoc), USA. | hsascuba.com |
| IAHD | International Association of Handicapped Divers, Holland | iahd.org |
| IANTD | International Association of Nitrox and Technical Divers, Inc. | iantd.com |
| IDDA | International Discovery Diving Association | i-d-d-a.com |
| IDEA | International Diving Educators Association Established 1952 as part of the Florida Skin Divers Association. | idea-scuba.com |
| ISDA | International Scuba Diving Academy, Italy | isdaworld.com |
| MDEA | Multinational Diving Educators Association, USA | mdeainternational.com |
| NACD | National Association for Cave Diving, USA | nacdmembers.org |
| NADD | NADD GLOBAL DIVING AGENCY (NADD) | naddeurope.com |
| NASE | National Academy of Scuba Educators, USA American-based. Draws its extensive experience from the fields of commercial, recreational, technical and cave diver training. | naseworldwide.org |
| NAUI | National Association of Underwater Instructors Worldwide organisation headquartered in America. | naui.org |
| NDF | Norges Dykkeforbund, Norway | ndf.no |
| NDL | National Dive League Russian organisation, member of the European Underwater Federation. | ndl-global.com |
| NOB | Nederlandse Onderwatersport Bond, Holland | onderwatersport.org |
| NSS-CD | National Speleological Society Cave Diving Section, USA | cavediver.org |
| PADI | Professional Association of Diving Instructors Worldwide organisation formed in 1966 and headquartered in America. | padi.com |
| PDIC | Professional Diving Instructors Corporation | scubaeducators.org |
| Pro Tec | Professional Technical Diving International | protecdive.com |
| PSAI | Professional Scuba Association International | psai.com |
| PSS | Professional Scuba Schools Conform to the directives of the European Community (EN Standards) and to ISO standards. | pssworldwide.org |
| PTRD | Professional, Technical and Recreational Diving Follow CMAS and RSTC standards and is ISO Certified by EUF. | ptrd.international |
| RAID | Rebreather Association of International Divers Rebreather and open circuit training. Use an e-learning programme. RAID training standards are compliant with ISO Recreational Diving Standards and is accepted by The UK Health and Safety Executive as an approved provider. They also offer Nationally Accredited training in Australia. | diveraid.com |
| SDI | Scuba Diving International Created in 1999 and grew out of sister company TDI, which specialises in the more advanced disciplines of technical dive training. Agencies that are accepted to meet the prerequisites for SDI include: IDEA, PADI, PDIC, SSI, YMCA, NAUI, BSAC, Sub Aqua Association, European Standard, CMAS and IANTD | tdisdi.com |
| SNSI | Scuba Nitrox Safety International, Italy | scubasnsi.com |
| SSDF | Svenska Sportdy Karförbundet, Sweden | ssdf.se |
| SSI | Scuba Schools International (Worldwide) In the Spring of 1999, SSI merged with the National Association of Scuba Diving Schools. | divessi.com |
| SSI TXR | SSI Technical Extended Range | divessi.com |
| TDI | Technical Diving International Agencies that are accepted to meet the prerequisites for TDI include: IANTD, ANDI, DSATI, SSI, NAUI, NACD, NSS-CDS, CMAS, BSAC and CDAA. | tdisdi.com |
| VDST | Verband Deutscher Sporttaucher E.V, Germany | vdst.de |
| WOSD | World Organisation of Scuba Diving | wosd.com |