Divers performing diving operations must hold a certificate proving that they have been subjected to a medical examination for divers which is valid for the diving operation concerned.
At intervals of maximum one year, it must be renewed by the diver being subjected to a medical examination and being found fit for diving operations.
In Denmark, medical examinations must be carried out only by special diving doctors who have been approved by the Danish Maritime Authority.
Guidance on medical examinations of divers (only available in Danish)