Over a year since Australia's international borders were slammed shut in the face of the COVID pandemic, overseas travel is making a cautious comeback – and an Australia-Singapore travel bubble remains high on the list.
It's been a topic of continued discussion between the Australian and Singaporean governments, even as sporadic outbreaks in each country give reason for pause.
As it happens, there's already a one-way Australia-Singapore travel bubble in place.
Travellers from Australia (along with other low-risk countries including New Zealand and Taiwan) can fly into Singapore, undergo a COVID-19 PCR test upon arrival in Singapore and isolate for the few hours it takes to return a negative test result.
However, when returning from Singapore to Australia, those travellers currently need to enter 14 days of mandatory user-pays hotel quarantine – and that's without even considering the challenges in getting booked onto a flight, given the current caps on overseas arrivals.
That'll obviously need to be upgraded to a bilateral two-way bubble before Australia-Singapore trips land back on the calendar.
Two COVID tests?
Even so, it's not a given that an Australia-Singapore travel bubble would be in the same 100% quarantine-free mode as the Australia-New Zealand bubble, which sees passengers walk off their flight with nothing more than a quick on-the-spot temperature check.
COVID testing plans for the forthcoming Singapore-Hong Kong travel bubble – which remains at risk ahead of its May 26 launch – might serve as a better example of what Singapore could insist upon for a two-way bubble with Australia.
This could include the requirement for a negative test result from pre-departure COVID-19 test taken within 72 hours before the scheduled departure of the flight rom Australia, along with that second test on arrival.
Reciprocal recognition of so-called 'vaccination passports' – even if only used to store the results of COVID tests – may also be a mechanism of the Australia-Singapore travel bubble.
The Lion City loophole
Quarantine-free travel to Singapore could also become another 'escape route' for Australians who have not been given permission to leave the country to fly on to other destinations beyond Singapore, as happened with the New Zealand bubble.
Considering that Changi Airport remains a hub for scores of airlines and routes, the Lion City would be even more appealing loophole.
Travel bubbles and similar COVID-safe corridors are increasingly likely to be the exit strategy from Australia's 'lockdown and lockout' approach which has brought international travel to a standstill.
But those bubbles are fragile, and even the Singapore-Hong Kong travel bubble could still burst if neither country can bring their seven-day moving average of unlinked cases below the mutually-agreed threshold of five per day.