Protesters in Venice are planning to disrupt a visit by the billionaire US ambassador to Italy in his 117-metre superyacht, which they fear he plans to dock in the lagoon city.

“We ruined the party for Jeff Bezos’s wedding last year – this year let’s ruin the ambassador’s tour!” said Stella Faye, a 28-year-old researcher and activist, at a meeting of about 40 demonstrators on Thursday.

In June last year, the ostentatious wedding of the Amazon founder and Lauren Sánchez was disrupted by Venetians protesting against what they saw as the takeover of their city by someone with enough money to do so.

Now the ambassador Tilman Fertitta can expect a similar welcome after it was revealed he plans to visit Venice with his personal superyacht on 17 July as part of a cruise around Italy’s coastline to celebrate ties between Rome and Washington and the 250th anniversary of US independence – a tour he has called “Coastal Diplomacy 250”.

One person suggested, to a round of laughter, “bringing back the crocodiles” – a reference to protesters’ threat last year to fill the canals with inflatable crocodiles, which forced the Bezos-Sánchez wedding reception to change venue at the last minute.

Activists fear Fertitta plans to dock in the historical centre of Venice for the Festa del Redentore, one of the city’s most important traditions and arguably its biggest party. Held on the third weekend in July, it celebrates the end of a 16th-century epidemic of bubonic plague that killed more than 50,000 people in just two years (more than the current official resident count of the city).

Every year, a temporary, floating bridge is built between the main island of Venice and the Redentore church on the island of Giudecca so Venetians can walk across the water to give thanks at the church. The main event is a spectacular firework display on the Saturday night, for which thousands of Venetians line the waterfronts and gather in boats in the Giudecca canal and in front of St Mark’s Square to watch the show.

“Redentore is one of the few occasions that still belongs to the people of Venice,” Faye said.

But Venetians could find their view somewhat obstructed this year. Fertitta’s yacht, Boardwalk, is a 32-metre-high, six-deck vessel equipped with two helipads and two swimming pools, reportedly worth $450m. According to the website of Venezia Terminal Passeggeri, which handles yacht mooring requests, the most central spots for a boat his size are off the Punta della Dogana – in front of the Redentore church – or on the Riva dei Sette Martiri, a popular viewing spot for locals.

“The city letting this yacht come to Venice would be a slap in the face for Venetians,” said Giulia Cacopardo, a 29-year-old activist and cultural coordinator. “In a city where quality of life is in tatters because there’s nowhere to live and only precarious jobs, we have billionaires thinking they can do whatever they want. It shows the arrogance of money – coming to a party for citizens that you probably don’t know anything about.”

During the meeting, many present bitterly reiterated the idea of Venice being a showcase – a stunning backdrop that can be temporarily bought by wealthy celebrities, entrepreneurs or politicians.

They also cited safety concerns, saying there was a risk local police would be focused on protecting the ambassador and managing boat traffic around the yacht, rather than on the smooth running of the event for Venetians. “This isn’t just an inconvenience, it’s a danger to the public,” Faye said.

The protesters have chosen the punning slogan “Venezia non si USA” (“Stop using Venice”), stressing that Fertitta’s role in what they call the “warmongering and colonialist” Trump administration is the main reason for their ire. Fertitta, an entertainment mogul who owns the NBA team Houston Rockets, has an estimated net worth of $14.2bn and helped fund Donald Trump’s 2024 presidential campaign.

Fertitta’s trip comes at a time of strained relations between Trump and Italy’s prime minister, Giorgia Meloni, which worsened when Trump claimed she had “begged” him to pose with her in a photo on the sidelines of the G7 summit, held in France in mid-June. Meloni shot back: “Neither I nor Italy ever beg.”

Fertitta downplayed the spat in an interview with the Italian TV channel Sky TG24 on Wednesday, saying the two leaders were “totally on the same page”.

The US embassy in Rome and the port authority in Venice have been contacted for comment.