The United States finally invaded Canada on Sunday, although the trespassing flotilla of dinghies, inner tubes and rafts was hardly the kind of invasion force one might expect.

Strong winds disrupted the annual Port Huron Float Down on the American side of the St. Clair River over the weekend, pushing nearly 1,500 participants in dinghies over the border and onto the shores of Sarnia, Ont. Most of the unintentional border-crossers arrived without passports, phones or arrangements to get back home, creating a major headache for law enforcement and emergency responders on both sides of the river.

"They were pushed over pretty quickly, and because they had no control over these dinghies and the wind was basically directing them and the current, they ended up over here," Sarnia Police Const. John Sottosanti told CTVNews.ca. He added that while some had paddles to keep themselves on course, "others tied numerous dinghies together to try and keep together and hopefully move as one, but they were not successful at all."

Police, border security and coast guard agencies from both sides of the border stepped into to help round up the wayward Americans and return them to Port Huron. Emergency response crews from several Sarnia chemical plants also helped with the situation, as a number of boaters landed near their facilities.

"It was pretty much a spontaneous reaction," Sottosanti said.

The Red Cross also helped out, as the boaters waited in cold, rainy conditions until they could be returned home. Those who could not arrange a ride back to the United States were transported there on 20 Sarnia city buses.

Sottosanti says all the stray boaters were accounted for in the end. "Everybody got home safe and sound."

Every year, participants in the Port Huron Float Down gather at Lighthouse Park, where Lake Huron feeds the St. Clair River. Participants launch themselves from the bank early in the day and ride the current south approximately 14 kilometres, to land at Marysville, Mich.

A "large percentage" of this year's participants ended up on the Canadian shore, more than any other Float Down in recent history, Sottosanti said. He added that the last case of several dinghies winding up in Canada happened in 2011, during a vicious storm that also caused a devastating tornado in nearby Goderich. Approximately 100 boaters ended up in Canada that year, he said. "Nowhere close to what we had here."

Port Huron Float Down organizers thanked Canadian authorities for their help on Sunday evening. "You've shown us true kindness and what it means to be amazing neighbours!" a post said on the group's Facebook page.

Several others thanked Canada for its hospitality and help in the post's comments section.

Sarnia Police tweeted several photos from the recovery effort.

Hundreds of individuals being shipped back by bus with police escorts. #sps pic.twitter.com/wE62MmCu77 — Sarnia Police (@SarniaPolice) August 21, 2016