Nuclear-powered submarine USS Minnesota slips quietly into Darwin Harbour

A US nuclear-powered submarine has pulled into Darwin Harbour, with authorities keeping the high-value vessel under close wraps from the public eye.

A US nuclear-powered submarine has pulled into Darwin Harbour, with authorities keeping the high-value vessel under close wraps from the public eye.

On Thursday morning, the USS Minnesota, escorted by a couple of tug boats, was seen passing through Darwin Harbour towards East Arm.

The clear sighting comes after more than 72 hours of speculation that a foreign submarine had been loitering in Darwin’s waters.

The USS Minnesota (SSN-783) docked at HMAS Stirling on February 26, 2025 in Rockingham, Australia. Photo by Colin Murty – Pool/Getty Images)

It is understood the USS Minnesota cruised to northern Australia directly from Perth, where it was docked at HMAS Stirling last month.

According to defence officials, the WA visit was used as an opportunity to give Australian sailors first-hand experience on the stealth vessel, which is the same type of submarine the ADF will receive under the AUKUS deal estimated to about $368 billion.

The Royal Australian Navy’s first Virginia-class submarine is expected to arrive in the early 2030s.

The USS Minnesota is not the only American warship taking port in Darwin, with the USS Emory S. Land also joining the nuclear-power sub.

The USS Emory is a submarine tender, tasked with providing specialist logistics support.

The arrival of both vessels has been kept highly confidential, with defence officials remaining vague on their presence or the activities they’re involved in.

Late on Thursday, a US Navy spokesperson confirmed no training was being conducted in Darwin Harbour and that no public viewing of the vessels would be held.

“The submarine tender USS Emory S. Land’s (AS 39) and the Virginia-class fast-attack submarine USS Minnesota’s (SSN 783) visit to Darwin is a demonstration of the ironclad bond we enjoy with our Australian allies,” they said.

“US Navy port visits to Australia and participation in military and humanitarian exercises emphasize the expanding wealth of knowledge and coordination between our two nations.”

Several submariners come up for fresh air in Darwin Harbour. Picture: Pema Tamang Pakhrin

Last week, the NT Government issued a ‘notice to mariners’, warning local boaties the waters surrounding East Arm Wharf would be closed due to a joint US navy and ADF operation which runs until April 3.

The notice warned any interference with the area would result in removal or arrest, with police on site around the clock.

The notice does mention whether the activities being conducted at East Arm are part of a training exercise.

Originally published as Nuclear-powered submarine USS Minnesota slips quietly into Darwin Harbour