CMAS (Confédération Mondiale des Activités Subaquatiques) is an international federation that represents underwater activities and oversees an international system of recreational snorkel and scuba diver training and recognition. Its foundation in 1959 makes it one of the world's oldest underwater diving organisations.
There are following CMAS freediving certification levels:
| 1*Star | 2*Star | 3*Star | |
| Prerequisit (age) | 14 years | 14 years | 16 years |
| Prerequisit (course) | 1*Star | 2*Star | |
| Requirement (STA) | 1:30 min | 2:30 min | 3:30 min |
| Requirement (DYN) | 25 m | 50 m | 75 m |
| Requirement (CWT) | 10 m | 20 m | 30 m |
| Number of Sessions | 4 | 4 | 6 |
Next to the CMAS freediving certification levels there are also other freediving certifications available from AIDA, PADI or SSI.
Sources:
http://www.cmas.org/document?sessionId=&fileId=4449&language=1 (Retrieved 03.04.2019)