Navigation radar aboard the Royal Australian Navy ship HMAS Canberra interfered with wireless internet and radio services across parts of New Zealand as the vessel approached Wellington, an incident reported on June 6, 2025. The Australian Defence Force said the ship changed frequency after becoming aware of the problem and that no disruption remained.
The interference occurred on Wednesday morning while Canberra travelled along the New Zealand coast before arriving in the capital on Thursday. Reports placed the affected area between Taranaki on the North Island and Marlborough on the South Island, spanning a broad region across Cook Strait. One local technology executive said problems began shortly after 2 a.m.
The radar signal appeared in spectrum used by internet providers and radio stations. Commercial operators detecting it had to stop using the affected channel, interrupting service or forcing them onto alternatives. New Zealand’s Defence Force contacted its Australian counterpart after the issue was reported, and both defence organisations later treated the matter as resolved.
Dan O’Grady, a radio-spectrum policy manager at New Zealand’s Ministry of Business, Innovation and Employment, said the interference occurred in a shared band. Some spectrum, including bands used for Wi-Fi and Bluetooth, is available without individual licence fees and supports multiple types of equipment. Sharing makes efficient use possible, but systems must also respond when a powerful or protected signal appears.
The practical effect varied by operator. BrianFM, based in Blenheim, said it switched to a backup system so it could continue broadcasting. Primo, a wireless internet and mobile telecommunications business, described disruption that moved across its network in line with the ship’s travel. Managing director Matthew Harrison said built-in safety protocols had been triggered by the military radar.
HMAS Canberra is among the Royal Australian Navy’s largest ships. The event involved its navigation radar, not a cyberattack or a deliberate attempt to block civilian communications. The Australian Defence Force characterised the interference as inadvertent, and the corrective action was a frequency change rather than a prolonged shutdown of the equipment.
The episode showed how systems with very different purposes can meet in shared radio spectrum. A naval sensor strong enough to support safe navigation also caused civilian devices to vacate a channel over a wide area. The evidence did not quantify the number of customers affected, the duration of each outage or any financial loss. By June 6, officials said services were no longer being disrupted, leaving the incident as a resolved but unusual case of cross-border spectrum interference.
