NZ and US navies carry out Far North joint mine sweeping exercise

Royal New Zealand Navy and US Navy divers prepare to locate dummy mines placed in Tauranga Bay, in the Far North, during a recent joint exercise

The Royal New Zealand Navy and the US Navy have been on a joint exercise in the Far North, clearing dummy mines from a picturesque bay, all while locals sat on the beach and looked on.

And Tauranga Bay has provided an ideal location for the two countries’ naval divers and hydrographers to hone their mine-clearing skills and processes.

Tauranga Bay, in Whangaroa, was the venue for two-week Exercise Nautilus, last month where the RNZN’s mine countermeasures capability element from HMNZS Matataua was joined by the US Navy’s Explosive Ordnance Disposal Mobile Unit One (USN EODMU1).

The contingent, of around 60 people - including chefs, engineers and communicators, set up base at a local camping ground.

Able Diver Petra Dye-Hutchinson, one of two of the Royal New Zealand Navy’s first female Navy mine clearance divers, ready to dive into Tauranga Bay

Two long-range high-speed Littoral Manoeuvre Craft (LMC) powered up the coastline from Devonport Naval Base in Auckland, to take part in the exercise, arriving in Tauranga Bay in less than five hours.

Chief Petty Officer hydrographic survey technician Ryan Hulse, Autonomous Underwater Vehicle (AUV) mission planner, said Tauranga Bay is an ideal location for such an exercise.

“There are lots of different environments. There are multiple littoral beach zones, a harbour for sheltered operations, deeper water close by, and because we brought the LMCs up, a marina around the corner.”

Dummy mine-like objects were placed in a variety of locations around the bay and the job of locating them started with hydrographers, who deploy AUVs to scan the sea floor, using side-scan sonar to identify objects of interest.

The results were displayed back at camp, where an AUV operator studied the suggestive shape of a sonar “contact of interest”.

The NZ and US navy teams gather for mission briefing during their joint exercise in the Far North

That information and location was passed to the divers, who then investigated each contact, confirmed what it was, and “disposed” of the mine.

Visibility underwater was mixed for the divers but hand-held Diver Underwater Search Systems helped them locate items.

The exercise was HMNZS Matataua’s biggest domestic exercise this year and hosting the US Navy was a good opportunity to further develop interoperability and interchangeability between the two diving units, Hulse said.

“It was also an opportunity to innovate and discuss initiatives to improve all of our mine warfare processes and procedures. They were very appreciative for the opportunity to come to New Zealand to work alongside us, rather than bumping into each other at overseas exercises. It allowed us to work closely alongside one another and get more involved in all aspects.

‘’Exercise Nautilus was a fantastic opportunity for HMNZS Matataua to further cement its global reputation as a highly professional and agile mine warfare force.

“We got to work side by side with our US partners, learning and collaborating. Both nations conduct very similar work, with similar equipment and it’s likely one day very soon we will be working side by side on an operation together.”

And while the navy staffers were carrying out some serious work on and under the water, it provided plenty of entertainment for the locals.

He said locals and campers were curious and sometimes there would be a line of deck chairs on the beach as people watched what was happening.

“People were really interested in what we do.”