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A man walks on the sand at Ontario Beach Park on the shore of Lake Ontario in Rochester, N.Y.Adrian Kraus/The Associated Press

Don’t talk about politics in the boat.

Since Leandro DaSilva launched Ontario Boat Charters in Rochester, N.Y., six years ago, that has been the rule aboard his vessels.

The 49-year-old has been boating on the lake since he was 13. The water became a place where he could leave the stress of life on the shoreline. He named his boat company after the lake to share his love of it with others.

But after U.S. President Donald Trump signed an executive order last week to rename Lake Ontario “Lake America,” Mr. DaSilva said he’s worried that the once-peaceful water his business relies on is now tied to political controversy.

“Any time you bring politics into anything, it’s going to divide people, and this new name will divide people more,” he said.

Google Maps changes ‘Lake Ontario’ to ‘Lake America’ in U.S.

Canadians have swiftly condemned Mr. Trump’s renaming of Lake Ontario, which straddles the border between Canada and the United States, as an attack on Indigenous culture and an imposition of American nationalism on a lake whose name hasn’t changed in nearly 400 years.

Across the water in Rochester, located 150 kilometres southeast of Toronto, Americans are also opposing the removal of a name that is interwoven with businesses and landmarks throughout the region.

The city council of Rochester issued a proclamation on Friday to maintain Lake Ontario’s name and defy the President’s executive order. The proclamation called the “stunt” a distraction from other issues Americans face, including housing and the economy.

“To ‘change’ the identity of this lake, after centuries of being known by a single name, is as childish as it is futile,” the proclamation stated.

Asked to comment on Rochester’s proclamation, White House spokesperson Allison Schuster said the lake’s new name reflects its heritage and place in the U.S.

“As the president said, the majority of the great lake’s volume sits in United States territory,” she said in an e-mail.

Trump signed an executive order to rename Lake Ontario. What does it actually change?

Rochester city council president Miguel A. Meléndez Jr., who brought the proclamation forward, said the name “Lake America” disrespects the people who know Lake Ontario and its Indigenous history.

The lake’s name originated from an Iroquois word meaning “beautiful lake” or “sparkling water.” French explorers initially used other names such as Lac Frontenac, but Lake Ontario became most commonly used on maps.

Mr. Meléndez said the city council needed to take a stand against Mr. Trump because the water is critical to peoples’ livelihoods and Canada is Rochester’s best neighbour.

“It’s something we shouldn’t be picking fights over at this point, and it was important for us to stand up and say something,” he said in a Monday interview.

While the relationship between Canada and the U.S. will need repair, Mr. Meléndez said, he hopes the bond across the water will stay strong and outlast one president’s decisions.

On its website, the city refers to Lake Ontario as the “sweetwater sea.”

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The Toronto skyline is seen across Lake Ontario from Fort Niagara State Park in Youngstown, N.Y.Adrian Kraus/The Associated Press

Rochester and Toronto once shared a direct connection through a ferry that travelled across Lake Ontario. A planned route between the two cities was first floated in 1979, according to The Globe and Mail’s archives.

In May, 2004, the ferry route was launched after Rochester bought a US$32-million boat. A month after operations began, two Globe reporters raced from Toronto to Rochester to see whether travel by water or land was faster. (The reporter travelling by car handily beat the one taking the ferry.)

But the ferry lost US$10-million in its first 10 months of operating and was ultimately shut down in 2006.

William Keeler, a librarian and archivist for the Rochester Historical Society, said the ferry helped bring the two cities closer together and was an example of cross-border co-operation during its brief existence.

But he also said losing the ferry illustrated Rochester’s shift away from relying on Lake Ontario for trade and instead using the nearly 200-year-old Erie Canal, which flows across upstate New York from Lake Erie to Albany.

Mr. Keeler said that Mr. Trump’s renaming of the lake is an insult to both Americans and Canadians.

“Trump is trying to add one more thing to his legacy,” he said. “The guy is an egomaniac.”

The name “Ontario” extended beyond the lake and has become a signifier for the region, he said. The town of Ontario, N.Y., is roughly 30 kilometres east of Rochester. Multiple beaches, hiking trails and businesses near the lake also incorporate the name.

When Matt Saxon, owner of Rochester-based screen-printing company Lake Ontario Press, saw Mr. Trump’s Friday executive order, he initially joked with customers that he would have to change his company’s name.

As the day went by, he got a flood of messages from customers asking for Lake Ontario-branded clothing to protest “Lake America” and preserve the original name.

Lake Ontario merchandise grabs attention on both sides of the border

On Saturday, he held a pop-up event inviting customers to have their own clothing screen-printed with Lake Ontario designs, and people lined up an hour before opening. Mr. Saxon said he printed at least 300 shirts – one of the best days his business has ever had.

“So many people wanted it,” he said. “There was no way I couldn’t do it. I was going to do something, but I didn’t think I’d be doing it that quickly.”

Mr. Saxon is already planning another event as demand for the designs continues, prompted in part by the lake’s name change starting to appear online.

Google updated its map on Saturday to show U.S. users the name “Lake America.” Canadian users still see Lake Ontario, while people in other countries are shown both names.

The web giant said in a brief statement Saturday that such updates “follow our long-standing policy for bodies of water with names that vary from country to country.”

On Monday, Mr. Trump also asked Apple to change the name on its maps app.

Regardless of what any map says, Mr. DaSilva said he will always refer to it as Lake Ontario. But he’s concerned that keeping “Ontario” in his company’s name will complicate his boating business with both names in use.

“This is something I have to think about, and I don’t want to spend my energy to change things,” Mr. DaSilva said. “Now, it’s really just a waste of time.”

With reports from the Associated Press