IT'S a long flight from Australia to New York, with 18 hours in the air.
So when I discovered my United flight stopped in San Francisco for a couple of hours enroute to the Big Apple, I asked the airline if I could stretch the layover to 12 hours and yes, I soon had half a day up my sleeve to stretch my legs and discover the city by the bay for the first time.
So, were 12 hours enough?
I needed to be back at the airport about 9pm for my overnight flight to New York so, I jumped on the handy BART (Bay Area Rapid Transit) train direct from the airport terminal to downtown San Fran in 30 minutes, arriving around 1.15pm ready for a busy afternoon.
I came armed with a checklist of things I wanted to see and do during my lightning visit - ride the city's famous cable cars, cycle over the Golden Gate Bridge, set eyes on the world's most infamous prison, Alcatraz, explore Fisherman's Wharf and Pier 39 by the harbour front and squeeze in a workout at a local gym, preferably with a pool, so I could stretch out, limber up and freshen up before my onward flight to New York.
I jumped aboard one of the quaint cable cars near the Powell St BART station like an excited child.
And what fun - slower than I had anticipated but a terrific way to take in the city's quirky charms and Victorian architecture.
Passing Lombard St - the world's most crooked street, with 10 sharp turns in one block - my cable car journey ended near the waterfront where I hired a bicycle from Bay City Bikes for my next adventure - an easy but exciting ride over one of the world's most famous bridges, the breathtaking Golden Gate Bridge.
I was on a tight schedule so I began my 13km cycle, which takes roughly 90 mins, from downtown, along a harbourside bike track, over the bridge and on to the pretty harbourside village of Sausolito where a ferry transfers you and your bike back to town.
Cycling over the Golden Gate was a real thrill, with the pea soup fog eventually clearing a little so I could actually see the bridge in all her glory.
The ferry ride back to San Francisco takes you close to Alcatraz, which was a maximum security prison from 1934 to 1964, housing notorious criminals like mobster Al Capone.
Back in town, I cycled along the foreshore to Pier 39, where a lazy colony of sea lions poses for the tourists every day, competing with fairground attractions that crowd the pier.
After my ride, I enjoyed take-away fish and chips from the nearby Fisherman's Wharf before returning my bike and catching a charming old street car to the YMCA Embarcadero, a multi-storey warehouse converted into an amazing health club boasting breathtaking views over the harbour which are suitably distracting as you strive to catch your breath while using the YMCA's gym, aerobic and yoga classes, swimming pool, jacuzzi, sauna and steamroom - and all for just $15.
There's nothing like exercising with the locals to make you feel like a local.
With the fish and chips worked off and feeling suitably revived, I headed to the nearby BART station early evening and was back at San Francisco Airport around 9pm when I grabbed a mid-evening bite to eat as I waited for the overnight flight to New York at 11.15pm.
So, yes, it is possible to see a city like San Francisco in a 12-hour stopover if you are reasonably fit and able and stick to the main drawcards and pre-plan your itinerary a little so you can hit the ground running, taking time every now and then to just stop to take it all in so it's not a blur.
You save on accommodation and you gain an enormous sense of achievement at having done so much in one day - so much that I slept like a baby the minute I took my seat on the plane that night!
For information on San Francisco, visit the city's official site at sanfrancisco.travel.
For direct flights to San Francisco and on to New York, visit united.com.
If you want to fly 'flat out' to the States, United's Business Class cabin offers lie-flat seat beds, a 39cm video screen for video and audio entertainment and multi-course fine-dining.
For bike rentals, visit baycitybike.com.
* The writer visited San Francisco with the assistance of San Francisco Travel and United Airlines.