Whanganui residents are likely to see considerable helicopter activity over and near the city this weekend (Saturday, 20 March and Sunday 21 March).

Three rescue helicopters from the region are taking part in exercises aimed at up-skilling air observers on techniques associated with locating objects from the air.

The helicopters taking part are the Taranaki Rescue Helicopter from New Plymouth, The Square Trust Rescue Helicopter and The Helipro Rescue Helicopter both from Palmerston North.

Activity for identifying land targets will centre on an area of native bush on the outskirts of the city near Aramoho, and the marine phase will be conducted about 1 km out to sea roughly 5 km northwest of Castlecliff.

The helicopters will be flying at various altitudes and may at times be down as low as 500 feet above land.

"Air observation technique is an acquired skill that takes time and practise to perfect. It has paid off in the past with lives saved," said Sergeant Bill Nicholson Police SAR Coordinator for the Central District.

Up to 40 SAR personnel will be attending drawn from helicopter crews, Police SAR, Land Search and Rescue, Surf Life Saving and Coastguard Volunteers.