The police dive squad is crossing Cook Strait to join in the search for a diver missing in the Marlborough Sounds.
The man was reported overdue around 10.20am today after he failed to resurface from a dive north of Stephens Island, near D'Urville Island.
Senior Sergeant Clare Robertson said the coastguard, search and rescue teams, and the police had been searching since the diver was reported missing.
She said the Police National Dive Squad left Wellington this morning on the police boat Lady Elizabeth.
Ms Robertson said the squad would join the search once it arrived at the scene.
She said boaties in the area had also been offering assistance.