Sydney: Beautiful one day. Trump-free and still beautiful the next.

Within minutes of arriving at Rose Bay's new seaplane terminal for a scenic flight on the morning after the US election, American tourist and Trump critic Debbie Saxe texted her sister: "Not planning on coming home."

The message was attached to a photo of a 1963 Canadian-made de Havilland DHC-2 Beaver, one of only 900 of these seaplanes in the world.

By the time the Beaver dropped Mrs Saxe and her husband, Jon, off for lunch at Cottage Point north of Sydney, the two Americans didn't look quite ready to emigrate but happy to linger.

"I might stay longer than ever, now I don't have to answer to people on the street," Mrs Saxe said.

In the last 24 hours, Immigration New Zealand received 56,300 visits from the US compared to its daily average of 2300, according to The Guardian. The Canadian government's immigration website crashed under the weight of inquiries.

The Saxes' flight over Sydney took off from a new seaplane terminal, which also houses a museum dedicated to the "Golden Age of Aviation" when the only way to travel internationally was by seaplane.

The Saxes are avid travellers, heading on to New Zealand for a week before returning home. Had they arrived in Sydney 80 years ago, the couple's international flight would have landed on the waters of 'Rose Bay Airport', Australia's first international air terminal located at the same site as the new seaplane terminal. For many years, the only way to travel by air to New Zealand was by seaplane.

Few Sydneysiders knew the history or that the original international airport employed hundreds of mechanics working under large hangars, said Aaron Shaw, the managing director of Sydney Seaplanes.

He hopes the company's museum will do more to raise awareness of the history.

"[Rose Bay] was chosen for its proximity to Sydney, and because it was the largest bay in Sydney Harbour," Mr Shaw said. It was Qantas' first Sydney base, and it was where the nine-day Kangaroo route, Sydney to London, departed.

"It was a service for the rich. The one-way airfare cost the equivalent of a year's annual average salary back then (about $75,000 now)," he said. "It was that or six weeks on a boat."

When the flying boat base opened at Rose Bay in 1938, Mascot was still a dusty aerodrome, said Matthew Holle, a curator with the Museum of Sydney.

"The Rose Bay terminal was the stepping off point for international air travel to and from Australia. Following World War II when most countries had ceased operation of flying boats, Rose Bay still played an important part in Australian aviation."

Until the late 1970s, flying boat was the only way to reach Lord Howe Island. "When an airstrip was finally built on Lord Howe Island in 1974 a unique chapter in aviation history came to a close," Mr Holle said.