Lethal sea drones strike for real and rehearsal

New Zealand's main military partners are weaponising sea drones and using them in actual attacks - video has captured the moment three uncrewed boats hit a naval pier in Iran on Monday in what was the United States' first-ever attack using sea drones.

The New Zealand Defence Force (NZDF) meantime has been testing drones to spot vessels off Fiji and the Coromandel coast, and its drone spending in Budget 2026 and upcoming experiments with new sea drones are focused on surveillance not combat.

Yet it says it wants to "fully exploit" all types of drones.Critics say it should not even be trying to get in step with the lethal push as that would only spread weaponised sea drones into the Pacific.

The push includes Australia last year moving to put $2 billion into a fleet of Ghost Shark armed underwater drones, and in recent weeks announcing a new project to weaponise subsea drones to patrol seafloor data cables - the first "signature" project of AUKUS Pillar Two involving also the US and UK. New Zealand has considered joining Pillar Two for several years but not done so.

Increasingly navies globally are switching spending from manned to unmanned weapon systems on the surface or undersea, though it is intensely debated just how much drones can do versus regular ships.

Follow the money

Canberra has boasted it is "leading the world in terms of autonomous underwater military capabilities".

One of the NZDF's top priorities is to show by next year it is able to fight alongside Australia in a near-future conflict across multiple domains (sea, air, land, space, cyber). Its top priority is to become more combat-ready and lethal - yet internal documents say its depleted workforce is a big barrier to that.

While Budgets 2025 and 2026 put the bulk of maritime taxpayer funding into keeping ships afloat and renewing the fleet in years ahead, NZDF has pledged "significant" new investments in lethality and uncrewed systems without disclosing just how much.

Its science section is known to be working with the Australians on the emerging tech, and the Ministry of Defence recently told MPs while it was not buying any fully autonomous weapons systems that did not preclude human-guided ones.

Asked about this, the ministry told RNZ, "New Zealand has and will continue to purchase and operate non-lethal systems (eg drones for the purposes of intelligence, surveillance or reconnaissance) and is considering procuring lethal but non-autonomous systems (such as strike drones under human control) in the future."

NZDF recently signed up for some sea drones described as "combat-proven" by local manufacturer Syos - its SM300 drones are used by Britain's navy in straits around Greenland - and it has also been looking at integrating drones with a firing control system. These are still being fitted out by Syos.

NZDF said it would use them to explore how the tech could support maritime awareness, surveillance and support activities.

Ukraine which has scored huge wins over the Russian conventional navy using sea drones, has offered to join New Zealand in a dronemaking joint venture, but the government has not taken it up on that.

NZDF told RNZ on Friday the focus was on putting missiles on ships, planes or vehicles.

"Future refreshes will consider expanding strike capability to other assets," it said when asked how lethal sea drones fit in.

Pacific historian and AUT law school lecturer Dr Marco de Jong said this was going the wrong way.

"Rather than buying into a spiralling arms race that we lack the industrial base to win, creating a regional non-proliferation regime would help to insulate New Zealand, and disincentivise major powers from deploying their military assets to our near region," said de Jong on Friday.

Rehearsals for sinkings

The NZDF's only known exposure to lethal sea drones is at recent US-led exercises.

The NZDF had 70 troops at exercise Balikatan in May where US-Filipino special forces sank an old ship using sea drones. It had an observer at NATO's Dynamic Messenger 2025 exercise that used Magura V7 drones like those that have hobbled Russia's Black Sea fleet in its war on Ukraine, to simulate the sinking of an alliance frigate. And the navy currently has 280 personnel at the world's largest maritime exercise, RIMPAC.

RIMPAC is running live-firing against a moving target from a missile launcher on a sea drone, as well as the largest delivery ever of parts by autonomous drones to 3D manufacturing plants aboard ships.

"This is exactly why I joined the Navy," 22-year-old able electronic technician Serenity Olive was quoted in navy PR speaking of RIMPAC.

Other wargames overseas - by desktop - have modelled how a "hedge" of sea drones could conduct distant anti-submarine warfare, offensive counter-air operations and anti-surface warfare to prevent threats from approaching Australia.

Another modelled an attack by China on Japan as part of a Taiwan invasion where Japanese sea drones struck at and distracted Chinese ships.

"Their use alongside more traditional weapons such as missiles meant the Japanese military still had more than half of its navy and aircraft several weeks into the conflict despite China's much larger force," said a commentary in Bloomberg.

China's 'swarm'

China is conducting its own sea drone exercises.

In March the People's Liberation Army was reported for the first time to have tested a "swarm" of sea drones off Guangdong - a video shows three small crewless boats said to share "collective intelligence".

The US is doubling down on drones as a whole, sea drones among them.

Last month the US set up a new Robotic and Autonomous Systems Combatant Command and a new drone-buying office with a budget over $90 billion to counter what President Donald Trump said was "millions" of drones being produced by adversaries each year. Uncrewed sea drones make up a quarter of its programmes.

The Trump directive behind all this is titled 'Unleashing American Drone Dominance' and states,

"Drones and autonomous systems are the most consequential battlefield innovation of this generation. The [Department of War] must move at the speed this moment demands."

Sizing things up

Against Iran, small lethal sea drones were used by the US on Monday against what it said were military targets. However, civilian infrastructure is not exempt from the threat.

Ukraine this week used navy drones to hit scores of vessels including tankers in the Sea of Azov aiming, it said, to disable not sink them, to disrupt Russia's oil exports and supply lines.

Not all sea drones that support warfighting are lethal themselves - the US Navy recently signed on seven companies including one that makes a transport sea drone, the Marauder, over 40m long.

Surveillance or survey can be another dual-purpose use. The Bluebottle drones the NZDF used last year to survey off Fiji in part achieved "proof of utility of uncrewed systems for Maritime Domain Awareness within the Pacific region" through "layered surveillance, over a prolonged period", a defence document said.

The two Bluebottles observed almost 250 vessels in 41 days at sea each.

Rules not drones

De Jong said proponents of lethal sea drones will say that New Zealand has a large Exclusive Economic Zone in the ocean and relies on seaborne trade so must enhance its naval capabilities to keep pace.

But "the pressing interest is in establishing rules", he said, and the foundation for that was in the country's coastal state rights under the United Nations Convention on the Law of the Sea (UNCLOS).

The choice was rules, not weapons.

"No Pacific Islands country currently operates lethal autonomous sea drones, nor would they seek to."

The rules-based approach was behind the South Pacific Nuclear Free Zone that became the Treaty of Rarotonga that outlaws nuclear weapons in the South Pacific and removed the region for Cold War geopolitical contests, he said.

He also cited the September 2025 Ocean of Peace Declaration of the Pacific Islands Forum that called on all states to promote "responsible use of technology and innovation".

"The instrument exists and there is a window of opportunity here."

Defence Minister Chris Penk told RNZ on Wednesday NZDF had to be able to support Pacific neighbours and "contribute to upholding the existing international rules-based order".

"New Zealand has long been supportive of a Pacific-led response to regional security issues and it is with that in mind we are exploring joining the recently announced Fiji-Australia Ocean of Peace alliance - which is a logical extension to what we already do."