With the towering bridges that span the Bosphorus choked by traffic, a new boat service from Uber aims to capitalise on Istanbul's infamous road congestion.

In partnership with local sea transport company Navette the Uber Boat venture is unlikely to net a significant chunk of the company's Turkey revenue, but it is further evidence of the strategy underpinning its offerings - making it easier to transport anything, in any way, by first booking a pickup through a mobile app.

"If we can get you a car in five minutes, we can get you anything in five minutes," said Austin Kim, local operations manager for San Francisco-based Uber Technologies, speaking over the growl of the speedboat engine.

But Uber boats are more expensive than boats parked next to Bebek pier where prices can often be haggled down even further.

Kim declined to give a precise number of boat users since the service launched on June 25, but said it was more than 100 trips. He denied the excursions were primarily a marketing tool.

Uber, whose backers include investment bank Goldman Sachs and technology giant Google, is valued in excess of $40 billion.

It says it offers its mobile phone taxi-hailing service in more than 300 cities, its prices varying according to demand.

Turkey's young and tech-savvy population tends to be an early adopter of technology. On land, Uber must compete with a popular home-grown taxi app, Bitaksi.

Having launched in Istanbul a year ago, Uber says it clocks up tens of thousands of rides a month in the crowded city on the junction of Europe and Asia.

The company has faced a backlash and legal clampdown in countries ranging from India to South Korea to France, where last week it suspended its UberPOP ride-hailing service after it faced protests and local authorities denounced it as illegal.

Uber speed boats have capacity of six to eight people and can be used to reach Atakoy, near Istanbul's main airport at a price of around 425 lira ($160) from a central pier, dodging hours of potential traffic jams over a distance of 17 km.

"It's at the choke point that you really suffer," Kim said, looking to one of the Bosphorus bridges. "You will not easily get onto that bridge in rush hour."