AMSTERDAM (Reuters Life!) - "O sole mio", sings a bemused road sweeper leaning on his broom as Tirza Mol rows along Amsterdam's Prinsengracht canal in the Netherlands' only gondola.

"People always think they're the first to make that joke," Mol says patiently. She'll be serenaded with impromptu opera a further three times within the next 20 minutes, along with chants of "Venice is that way".

The 38-year-old built the 11-metre boat herself as part of boat building studies in Amsterdam, after spending four months in Venice in a master gondola builder's boatyard.

"We weren't allowed to do anything there or touch anything... it is like a medieval system, one son had been working there for 25 years before he was allowed to build his first gondola."

She returned to Amsterdam, often dubbed the "Venice of the North" to build the boat, then headed back to Italy to learn how to row -- finding many doors closed to her due to her gender.

Eventually she found a teacher but she wasn't allowed to row into the centre of Venice.

"I went in secretly but was always caught by somebody, and they'd get angry," she said.

Today she is one of a handful of female gondoliers, she says -- all women from northern Europe.

"No Italian woman would want to do that."

Although Mol finished the gondola several years ago Amsterdam water authorities have only now said it can be "officially tolerated" on the canals, after confusion over how to classify it and fears they could see a whole fleet of gondolas arriving, her partner Hans Lentz explains.

Although the sleek, black gondola has now joined the tourist tourboats, noisy motorboats and panting tourists in pedalos all jostling for a spot on the water, Mol says she doesn't intend to build anymore.

"Gondolas should stay special to Venice."