Search and rescue staff are due to be out in force in Christchurch this weekend, but on this occasion it is just an exercise.
Coastguard units, Surf Lifesaving, Land Search and Rescue and police search and rescue personnel will be involved in Exercise Canterbury Tawhiri 2011.
Canterbury police Search and Rescue co-ordinator Sergeant Ryan O'Rourke says the large-scale marine search operation will provide the opportunity to test procedures and communications in a realistic way.
He says most of the marine operations carried out are of a short duration and personnel don't often get an opportunity to do extended searching.
Sgt O'Rourke says the exercise will be coordinated from the Sumner lifeboat base, but the scenario is being kept confidential to make it as realistic as possible for participants.