Moving from Garden Island to Port Kembla would force the Royal Australian Navy to sever a connection established more than 200 years ago.

That naval connection began just 10 days after the First Fleet landed, when Captain Arthur Phillip allocated the island to HMS Sirius for use as a ship's garden.

By 1800 it also housed a gun emplacement to defend the harbour from Russian attack and was regularly used to berth ships from the Royal Navy.

It became the nation's premier naval facility in 1913 and was expanded to such an extent during World War II that it was joined to the mainland.

Today, it is one of two main naval bases in Australia - the other Fleet Base West at HMAS Stirling near Perth.

Fleet Base East - the official name for Garden Island - is now home to 13 warships, including HMAS Canberra, an amphibious assault ship that, at 27,000 tonnes, is the biggest ship in the navy's fleet.

It also boasts the Captain Cook Graving Dock, one of the largest dry docks in the southern hemisphere.

But pressure has been building to find a new home for the Garden Island fleet. Some of that pressure has come from the cruise industry, with cruise-ship visits increasing every year.

Garden Island provides suitable docking space and some cruise liners already dock there under a special agreement with the navy.

There is pressure too from property developers, who see Garden Island as valuable land for residential purposes.

There is also some pressure from the navy itself because, as the fleet gets bigger, Garden Island begins to run out of space.

Alternative naval bases have been floated over the years - Jervis Bay was considered in the 1980s, and former prime minister Kevin Rudd announced during the 2013 election campaign that he was looking to relocate the base to Brisbane.

Last month, in a submission to the Defence White Paper on the nation's future defence capabilities, Illawarra-based senator Concetta Fierravanti-Wells raised the idea of Port Kembla being the navy's new home on the east coast.

"I believe the time is now right to give serious consideration to relocate the Royal Australian Navy [RAN] Fleet Base East from Garden Island to Port Kembla," Senator Fierravanti-Wells wrote in her submission.

"As a naval base and support facility, Garden Island is under continued and growing pressure to move from the Sydney area.

"Port Kembla offers an excellent opportunity for the RAN to establish a permanent base and support facility for its eastern fleet at significantly less recurrent cost to the Commonwealth over the long term.

''Whilst there are infrastructure and other relocation costs, these would be offset by the longer term savings including housing and personnel costs."

Senator Fierravanti-Wells' submission was prepared by her husband John Wells, who spent 35 years in the navy.

The submission said the Port Kembla harbour would be deep enough to accommodate HMAS Canberra, but admits upgrades to facilities would be needed to bring it up to naval standards.

It lists the proximity to bases like HMAS Albatross and Creswell, as well as that of the East Australian Exercise Area, as advantages possessed by Port Kembla.

Further advantages include the lack of residential development close to the port, security, and the plans already under way for developing the outer harbour.

"Noting the planning activities by NSW Ports with early stages of development of the Outer Harbour Port Kembla now under way, a window of opportunity may exist for the Commonwealth to engage the NSW government in order to facilitate the relocation of the principal east coast naval base of the RAN (and home port to many of the RAN's major ships), to Port Kembla," the submission reads.

Moving the navy to Port Kembla would truly be a "game changer" for the region, as Wollongong Lord Mayor Gordon Bradbery put it.

The Department of Defence stated there were more than 1900 naval personnel and roughly 1200 non-naval personnel stationed at Garden Island. These figures do not take into account those personnel attached to the berthed ships.

A 2011 KPMG report calculated the economic benefit those personnel bring.

Based on reported activity in 2008-09, Garden Island contributed $527.6 million to the economy, and supported 6784 direct and indirect jobs.

"It would be a game changer for Wollongong," Cr Bradbery said.

"From my perspective it would also be a stimulus for the local economy and also the housing supply and land at West Dapto would have to come into play pretty quickly.

"It would create a lot of opportunities for Port Kembla, but also the entire city and region. It ties in well with the fact the navy has a large presence in the Shoalhaven with Albatross and Creswell, so the links between those two sections of the Australian navy would be facilitated."

Port Kembla Chamber of Commerce president Ian Fulford was more reserved about the idea of moving the fleet to Port Kembla, given the massive infrastructure costs.

"If they're talking about the naval vessels themselves, probably one of the concerns that we have would be the infrastructure that goes with it," Mr Fulford said.

"Where are these people going to be housed? Is there ample infrastructure and accommodation as well for itinerant sailors coming and going, as well as permanent staff down here?

"I don't know how much thought's been put into the idea, but we're talking about significant changes to the infrastructure in Port Kembla as well as greater Wollongong."

There would also be the issue of the 99-year-lease NSW Ports has over Port Kembla. A spokesman from Ports declined to comment on this story, but presumably the move would result in that lease being overridden.