Police dive teams have been searching for a woman who went diving for crayfish in North Canterbury this morning and has not been seen since.
The 37-year-old woman started diving with a friend about 9.10am.
Search and Rescue has been concentrating on a drift pattern area provided by the Rescue Coordination Centre.
Police said Waimakariri and Ashley Coastguards and the local rescue helicopter searched the drift for an hour before the helicopter returned to Christchurch.
The search is expected to resume in the morning.