The ISO standards behind diver training.

Why standards matter to a new diver

Every agency writes its own courses and gives them its own names. The ISO recreational diving standards sit underneath, describing what a diver or instructor at a given level must be able to do. When an agency says a course meets an ISO standard, that is the agency's statement about its own programme. SSI, for example, titles its entry-level standard "Open Water Diver (ISO 24801-2)" and lists programmes it aligns with ISO 11121, ISO 24801 parts 1 to 3, ISO 24802 parts 1 and 2 and further ISO diving standards. NAUI names its supervised course "Scuba Diver (Supervised Diver, ISO Level 1)".

A search summary of the ISO catalogue says ISO 24801-1 was published by ISO technical committee ISO/TC 228 (iso.org itself could not be read). The edition details below come from the Estonian national standards catalogue, which lists the ISO and European versions.

The family at a glance

ISO 24801: the three diver levels

ISO 24801 is titled "Recreational diving services: Requirements for the training of recreational scuba divers". The Estonian catalogue lists all three parts as 2014 editions, valid from 31 March 2014, replacing 2007 editions. Search summaries of the ISO catalogue say that Part 1 is the second edition, published in April 2014, and that Parts 1 and 2 were last reviewed and confirmed in 2024.

According to the catalogue descriptions, each part sets out three things: the competencies a diver must reach before a training organisation issues that level of qualification, how those competencies are evaluated, and the conditions under which training is given. These sit on top of the general service requirements in ISO 24803. The standard applies only to training and evaluation in recreational scuba diving.

Wikipedia (secondary) outlines the content of Part 2, the autonomous level, as prerequisites (age and health), theory, confined water and open water skills, practical training parameters and evaluation. Its theory list includes equipment, physics, decompression management and planning, medical and psychological problems, the environment and nitrox use. Wikipedia gives EN 14153-2 as the European equivalent.

Australia adopted Part 3 as AS ISO 24801.3:2021. A search summary of its contents lists prerequisites, theory, personal scuba skills, leadership skills, rescue, first aid, evaluation and a minimum age for leading.

Which agency cards sit at Level 2

Wikipedia (secondary) lists certifications it maps to the autonomous diver level, including PADI Open Water Diver, SSI Open Water Diver, CMAS One Star, SDI Open Water Scuba Diver, NAUI Open Water Scuba Diver, BSAC Ocean Diver and GUE Recreational Diver Level 1. Many of those entries are marked "citation needed" in the article, so the list is a guide, not an official register. Wikipedia's diver certification article also points out that entry-level grades are not always equivalent between agencies, even where frameworks like ISO 24801 exist to compare them. See certification levels for each agency's ladder.

ISO 24802: instructors

ISO 24802 is titled "Recreational diving services: Requirements for the training of scuba instructors" and has two parts, Level 1 and Level 2, both current as 2014 editions. Each specifies the competencies an instructor must have before a training organisation awards that instructor level, with evaluation criteria and training conditions, again alongside ISO 24803. The Estonian catalogue gives their European predecessors as EN 14413-1:2004 and EN 14413-2:2004.

ISO 24803: dive providers

ISO 24803:2017, "Recreational diving services: Requirements for recreational diving providers", is valid from 8 March 2017 and replaced the 2007 edition. It sets requirements for businesses that provide recreational scuba and snorkelling services, covering the nature and quality of the service to clients. The catalogue names five kinds of service:

• introductory diving
• snorkelling excursions
• training and education
• organised and guided diving for qualified divers
• equipment rental

Freediving is outside its scope. A search summary of the DIN catalogue says it was adopted in Europe as EN ISO 24803:2017 and nationally under names such as DIN EN ISO 24803 and NF EN ISO 24803.

ISO 11121: try dives

ISO 11121:2017, "Recreational diving services: Requirements for introductory programmes to scuba diving", sets the minimum content of an introductory dive that takes participants into open water, according to a search summary of the ISO catalogue. Programmes run only in a pool or confined water are outside its scope, and it is not a qualification standard: a try dive under it does not make anyone a certified diver. The same summary says it was reviewed and confirmed in 2022. Agency try-dive programmes are compared on try diving.

Where the training councils come in

The WRSTC says its member councils hold positions on standards bodies, including the ISO diving standards group and ANSI. Wikipedia (secondary) adds that in 1991 the US RSTC became secretariat for an ANSI underwater safety committee, later replaced by the Z375 Diving Instructional Standards and Safety committee, and that it kept its role as an ANSI accredited standards developer in 2007. The US RSTC also publishes its own minimum course standards, from an Introductory Scuba Experience up to Instructor Trainer. Equipment standards, such as those for regulators and cylinders, are a separate set covered in the equipment section.