It is essential that the Diving Supervisor has a good understanding of IMCA D067.

It is recommended that in tidal waters current meters should be deployed to provide diving supervisors with accurate information about the true speed and direction of currents in real time.

Diving operations can usually be considered if the current is 0.7 knots or less.

– Diving in a current of 0.7 knots should not commence if the current meter is showing an increasing trend.

– Subject to the judgement of the diving supervisor, diving operations may commence in currents above 0.7 knots (up to a maximum normal operating limit of 1 knot) if the current is showing a decreasing trend.

The normal operating limit for diving operations is a current speed of 1 knot.

– Diving in currents between 1 and 1.2 knots should not be considered as a normal operation.

– Diving in currents above 1 knot should only be considered in exceptional circumstances and only

when the diving operation has been pre-planned taking account of the presence of strong currents.

Diving operations should not take place in currents above 1.2 knots.

IMCA D067. The effects of underwater current on diver performance and safety