Pupils from across Barking and Dagenham hopped onboard to mark the launch of the borough's new stop on the Uber Boat by Thames Clippers service.
Barking Riverside pier is the latest addition to the network, which has 24 stops along the Thames.
The children and staff were given the opportunity to board a river bus that took them into central London and back to the pier.
The experience was arranged by Barking Riverside Limited, Barking and Dagenham Council and Uber Boat by Thames Clippers.
Council leader Darren Rodwell called the new service "an important step in the regeneration of our borough".
"Its benefits will be felt far beyond Barking Riverside," he added.
“This event is a unique opportunity for the borough’s greatest asset, our young people, to learn more about their city."
People will be able to use the service from Barking Riverside to reach Woolwich in nine minutes, Greenwich in 28 minutes, Canary Wharf in 40 minutes and central London in 51 minutes.
The pier itself was delivered by Barking Riverside Limited, a joint venture between L&Q and the Mayor of London.
It is delivering the Barking Riverside development, which will include more than 10,000 homes and seven schools when complete.
A new London Overground stop serving the site is set to open later this year.
Barking Riverside Limited's managing director Matthew Carpen said: “One of our greatest ambitions for Barking Riverside was that the development should make the River Thames more accessible to everyone.
"This fantastic new river bus service opens up a whole new way for east Londoners to travel, making the most of our 2km of river frontage on site.
"I’m so pleased that this large group of school pupils from Barking and Dagenham have been some of the first to experience and enjoy the new service."
Sean Collins, chief executive of Uber Boat by Thames Clippers, said thousands of people had used the service since the pier opened last month.
He added: “We are thrilled to be introducing river bus services to Barking and Dagenham’s residents.
"It’s fantastic that the local community can once again enjoy being transported by river and its frontages in ways they haven’t been able to for many decades.”
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