Extinction Rebellion, which has targeted government buildings over the last few days, said protesters would lie, sit or glue themselves to "nonviolently use their bodies to close the airport".
Mr Masters said: "I would like to thank all the well wishes I have received since Monday evening".
The Czech branch of the Extinction Rebellion environmental movement will block traffic and hold protest gatherings in Prague to draw attention to the climate crisis from Thursday, October 10 to Saturday, October 12, the movement informed on social media on Wednesday.
The boat bore the logo of the activist group Extinction Rebellion.
Passengers on the CityJet aircraft, operating under a lease arrangement as Aer Lingus Flight 283, left the plane at the request of the captain before being allowed to board again, the spokesman said.
The group said its members planned to "peacefully occupy and shut down" the airport's terminal building from 9am on Thursday by lying, sitting or gluing themselves in front of the departure and arrival gates at the east London airport.More news: Kim Kardashian says Prince Harry and Duchess Meghan are 'changing the world'
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However, despite the scene on board the flight and scores of activists blocking the way for passengers at the airport's main entrance, staff clime flights are operating as normal.
A London City Airport spokesman said the captain exercised his right to arrest the passenger under worldwide flight safety rules.
"We continue to work closely with the Metropolitan Police to ensure the safe operation of the airport, which remains fully open and operational", he said.
Newsnight political editor Nicholas Watt, who was on the flight, tweeted to say that a "smartly dressed man in late middle age" stood up to deliver a lecture on climate change in the aisle, and politely declined to take his seat when asked to by cabin crew.
Cars and buses were backed up in both directions before the demonstrators were cleared from the roads by police.
London police have made hundreds of arrests as the protesters, labelled "unco-operative crusties" by Prime Minister Boris Johnson, began two weeks of civil disobedience.
The protest proceeded down Pearse Street onto Tara Street and then cross the river going around the Customs House to make its way to the Extinction Rebellion camp at Merrion Square via Lombard Street and Westland Row.