A scuba diving instructor in the right place at the right time is being credited for saving a drowning diver in West Vancouver's Whytecliff Marine Park on Sunday.

The instructor was teaching a class in the waters at the mouth of Howe Sound near Horseshoe Bay when he and his students heard calls for help nearby.

He wasted no time in organizing a grid search for the 46-year-old Port Moody woman after her partner surfaced, pleading for help around noon.

The instructor found the unconscious woman in about 14 metres of water within minutes.

He brought her up to the surface and pulled her to the beach, where CPR was administered.

The woman was taken by air ambulance to Vancouver General Hospital.

West Vancouver Police are now examining to see if the woman's equipment was functioning properly.

The victim's condition is unknown.