From the ISO 24801-3:2014 "Dive Leader" Standard, i.e. DM.
11.3 Minimum number of open water dives
To be certified as a scuba diver level 3, the student shall have logged at least 60 open water dives or 50 open water dives with a total accumulated underwater time of 25 h. At least 40 of these dives shall have been completed after level 2 in accordance with ISO 24801-2.
At least 30 open water dives shall include as wide a range of environmental factors as possible to ensure that the student has a wide range of experience. Examples of more demanding environmental factors can be:
— low visibility (less than 2 m horizontal);
— currents (more than 0,25 m/s (approximately half a knot));
— cold water (less than 10 °C).
If the local environment does not include any such factors, the candidate’s diving experience should be broadened by completing a greater number of dives and/or including dives of greater depth (e.g. more than 30 m).
11.3 Minimum number of open water dives
To be certified as a scuba diver level 3, the student shall have logged at least 60 open water dives or 50 open water dives with a total accumulated underwater time of 25 h. At least 40 of these dives shall have been completed after level 2 in accordance with ISO 24801-2.
At least 30 open water dives shall include as wide a range of environmental factors as possible to ensure that the student has a wide range of experience. Examples of more demanding environmental factors can be:
— low visibility (less than 2 m horizontal);
— currents (more than 0,25 m/s (approximately half a knot));
— cold water (less than 10 °C).
If the local environment does not include any such factors, the candidate’s diving experience should be broadened by completing a greater number of dives and/or including dives of greater depth (e.g. more than 30 m).