The drill was sprung on Endeavour's crew without warning at 2pm, as the vessel - in Dunedin on a four-day rest and recreation visit - was tied up alongside the T/U Sheds in Dunedin's upper harbour.
Alarms sounded and puffs of smoke came from the replenishment tanker's smokestack as those members of the crew not enjoying their R&R ashore were called to tackle the imaginary inferno.
Firefighters from the Dunedin Central station cordoned off the wharf and poured water on the ship's side, while others wearing breathing equipment went aboard to assist the crew.
Police were also on hand, as were St John ambulance staff, who treated two crew members with simulated injuries.
The drill, which lasted just over two hours, was organised by members of the Royal New Zealand Navy's mobile operational evaluation team, based at the Devonport Naval Base in Auckland.
Lieutenant-commander Mark Tapsell said the drill aimed to provide a "snapshot" of the crew's readiness for such an emergency, and he was pleased with their performance.
He and other members of his team had announced they would be joining the vessel's crew from today to conduct a series of tests and exercises while at sea.
However, after liaising with the Fire Service in Dunedin for the past month, they surprised the crew with yesterday's exercise, he said.
"It's a huge exercise that requires significant man-management.
That's what they are trained to do, but it's not very often they get the chance to conduct an exercise of this magnitude," he said.
It was the first time since 2003 such a drill had been held in Dunedin, and also provided the crew and emergency services with invaluable experience working together, Lt-cmdr Tapsell said.
It was likely to become a more common occurrence across New Zealand, as the arrival of the navy's Project Protector fleet meant more frequent visits by the navy's new vessels and their crews, he said.
Dunedin Central Chief Fire Officer Dave Seque said the exercise was of "huge benefit", with many of the firefighters involved working inside a navy vessel for the first time.
The environment was "a bit different from a building", with firefighters having to make their way down confined corridors below decks - into the rising heat of any real fire - to tackle its source, he said.
