Searches for two swimmers missing since Saturday in separate incidents have failed to find any trace of the men.
The dive squad on Monday joined searchers using boats and helicopters to look for Duane Kaka.
The 34-year-old was with a group of canoeists when he decided to swim across the Whanganui River.
Police say the fast-flowing, murky water from recent downpours has made the search difficult, particularly for the dive team.
Members of the dive squad also spent several hours at Titahi Bay beach, near Wellington, searching for Albert Alapati.
A Department of Conservation ranger planned a further shore search around Mana Island for the 24-year-old on Monday evening.
Searches for the men will continue on Tuesday.