Boaters planning to float down the Detroit River are being warned to notify officials if they cross the invisible border before coming back to Canada.
The caution comes courtesy of a new interpretation of the "in transit exemption," according to former commodore of the Windsor Power and Sail Squadron, Alan Johnson.
"Call in more frequently than you probably think you probably should, and make sure you have all your identification with you and a phone or radio with you so you can call in," said Johnson, adding his advice applies to everyone on the water, from boats to paddle boards.
"When you cross the ... dotted line, you are supposed to call back in upon entering Canada," he explained.
Word of the change comes after a recent meeting between Windsor boaters, RCMP and officials from both sides of the border where Windsor residents expressed confusion over the rules.
In a statement sent to CBC, the CBSA said failure to report returning to Canada could lead to detention, seizure of a boat or a hefty fine.
"The minimum fine for failing to report to the CBSA upon entry to Canada is $1,000," the statement said.
Johnson said Canada's regulations are actually more strict than those of the Americans, who only expect boaters to check in if they drop anchor in the U.S. or come ashore.
"I believe the law was always there," he said, adding he believes more people have been caught by the coast guard for not checking in. "It's just it's kind of being more enforced and interpreted to the letter of the law right now."