Two Jet Cats sit gurgling deep-throated on their twin pontoons, like some fat species of marine life, taking on tourists and city dwellers down at water's edge on Circular Quay in downtown Sydney.
The captain of one of them nicks up the speed of the catamaran's big diesels into a drone and begins backing the Cat, loaded with a couple of hundred people, into Sydney Harbor, where the fun begins.
When viewed from out on the water, Sydney rises beyond the snap-shot beauty so often seen on calendar pictures taken from the air, wearing its skyline and waterline like a hemline, with a svelte naturalness that sets it apart as Australia's architectural gem.
Small waves roll past as the Jet Cats' engines purr, and the Sydney Opera House rises into view, its graceful arches larger and far more powerful against the city's skyline than on zillions of post-card shots.
Looming overhead is the immense Harbor Bridge and Sydney Tower (at 1,000 feet, the Southern Hemisphere's tallest building). Past the Opera House, the lush fringes of the Royal Botanical Garden, a tropical paradise, come into view along the shore.
Chosen as the site for the 17th summer Olympics, Sydney is a city of 3.4 million people with an architectural complexity that gives it the sort of special character Australians want to hang onto - even if it means giving up on a few extra fast-food franchises.
James Colman, a local architecture critic, worries that the architectural character and integrity of Sydney is increasingly falling prey to the bright plastic signs and gaudy colored awnings of McDonald's and Kentucky Fried Chicken, which increasingly pop up along the busy streets in downtown Sydney.
"We've had English, American, and other architects and corporations coming down here for donkey's years," he says. "A few years ago they were proposing a huge flashing neon sign that said 'Coke' from the top of a local building. This is what we're fighting every day."
But Peter Romey, senior heritage architect for the Sydney city council, says measures are being taken to limit the impact of American franchise design on downtown Sydney streets like George and Pitt.
"The corporate approach is that every one of their franchises is identifiable and looks the same," he says. "But with heritage buildings you have to take a merit approach. By and large, these companies have responded to limit the proliferation of corporate packaging of our buildings."
Like Boston, Sydney is a fascinating place to stroll through because of its complex pattern of narrow streets that developed slowly in the years after 1778, when Captain Arthur Phillip named a tiny inlet within Port Jackson, a British colony, Sydney Cove.
Another good way to get the lay of the city, besides walking or from the water, is by taking the monorail. It runs in a loop above the streets between Darling Harbor and City Center.