Robotic "drone" spy planes flying by remote control could be used to patrol New Zealand's waters.
The Defence Force is keeping a "watching brief" over the unmanned planes, some of which have the range to conduct surveillance in the Southern Ocean around Antarctica, and in the Pacific Islands.
Drones are best known for their use to fire missiles against militants in Iraq and Afghanistan.
But their ability to spend up to 32 hours in the air and send back video images means they could take up the Air Force's role of monitoring New Zealand's exclusive economic zone and neighbouring waters for illegal fishing boats, and even search for lost vessels.
The New Zealand Army has developed its own hand-launched drone, the Kahu, which is almost ready for soldiers to use for "over the hill" observation in battlegrounds such as Afghanistan.
The head of the Army's capability staff, Colonel Phil Collett, said the Defence Force was assessing drones "to find out what questions we should be asking to become an informed customer".
The force "certainly thinks there is a place for this kind of technology", he said.
It was examining how drones could be used by the Navy, Army and Air Force.
Colonel Collett said drones ranged from "global roaming aircraft that can stay in the air for days at a time, to the type of things soldiers might use to look over the hill in front of them".
The Kahu - Maori for hawk - was a "home-grown" drone developed with private interests. It recently had a night flight.
Defence Minister Wayne Mapp said that as well as the "watching brief", drones would probably be considered in the upcoming Defence White Paper, which will shape the future function and resources of the armed forces.
Dr Mapp said the US Coastguard and Australian Government were looking at using drones for sea patrols.
The US Coastguard wants an unmanned helicopter that can be launched from ships, and Australia has tested several drones, including the long-range Global Hawk.
The Australian Government this month rushed through a multi-million-dollar deal to lease two mid-range Heron drones for use in Afghanistan, where its troops are already using the hand-launched version.
Its Air Force has said it aims to have another drone for maritime surveillance by next year.
Dr Mapp said the use of drones had been raised several times at public consultation meetings being held for the White Paper.
They were "clearly one of the things we have to think about", Dr Mapp said, but he did not want the White Paper "turning into a shopping list".
He said being unmanned did not make the drones cheap, as they still required a pilot and support crew on the ground.
He said a top-end version with satellite links would be needed to monitor New Zealand's exclusive economic zone which extends 370km from the shore and is one of the biggest in the world.
It becomes even bigger when international obligations in the Southern Ocean and Pacific are factored in.
Dr Mapp said two manned planes could do a similar job, "with the added advantage that you can change mission and throw a liferaft out".
Drone technology is advancing rapidly, and the US Air Force is now training more drone operators than fighter and bomber pilots in what is seen as a fundamental shift.
Dr Mapp said New Zealand needed military resources with flexibility, and the advances being made with drones could provide this.