Canadian clearance divers use diving equipment like this to carry out mine countermeasures work along with other underwater duties.

The equipment seen here is a "rebreather", drawing on Second World War experience, that re-circulates the gases the diver breathes so as not to emit large clouds of bubbles that could be detected by an enemy. The equipment is also silent and non-magnetic to avoid detonating mines triggered by sound or the presence of metal. Canadian clearance divers have used several models of "rebreather" during the decades following the Second World War, and continue to use such equipment today.

Naval Museum of Alberta