An inquiry has begun into the presumed drowning of a soldier on Tuesday in Lake Moawhango, near Waiouru.
Private Michael Ross, from Linton Military Camp, fell from an inflatable boat into the lake about 5.30pm, while on small boat training in the Waiouru Training Area and has not been seen since.
Police believe about six people were on the vessel at the time.
About 100 people searched on Thursday for the 29-year-old Kaitaia man, with the navy dive squad making sonar sweeps of the lakebed, 42 metres down.
The search will resume at first light on Friday.
Defence Minister Jonathan Coleman says a Court of Inquiry is underway into the tragedy but he expects the army's amphibious training will continue.
"I would expect that training would continue because at the end of the day they've got to be ready for the task they got to perform."
Ruapehu area commander Inspector Steve Mastrovich says investigators are talking to people who saw Private Ross fall overboard to try to find out why Private Ross went missing so quickly.
Family members have been informed.
Private Ross, a rifleman, joined the Army in August 2009. He served in Timor Leste last year.