The Navy says police will make the final decision on whether to try to recover plane wreckage and the bodies of the 2degrees chief executive and his wife.
The dive support vessel HMNZS Manawanui is on its way to the site off Kawhia where Eric and Kathy Hertz's twin-engine plane plunged into the sea on Saturday.
The couple were flying from Ardmore near Auckland to Timaru when they reported engine problems on the Beechcraft Baron.
The aircraft is upside down and embedded in the ocean floor at a depth of 56 metres.
Worsening weather is preventing any further exploration of the crash site on Thursday.
The Navy ship's commanding officer, Lieutenant Commander Kerry Driver, says the vessel is well equipped and has highly trained divers.
Lieutenant Commander Driver said a crane onboard the vessel can lift the wreckage from that depth but whether to do so will be a decision for the police to make.
He expects the HMNZS Manawanui to arrive at the site on Friday morning and says they will decide then whether to let divers enter the water.
