Violent waves and high winds threatened between 80 to 100 students from local high schools, and McMaster student rowers on the water this morning, capsizing at least seven boats and spurring a frantic air search. Thirty people were plucked from the water by Hamilton and Halton marine units.

Police have confirmed all students, including coaches and rowers from Leander Boat Club, primarily members of Mac’s senior rowing club have been accounted for.

Nine rowers were taken to McMaster University Medical Centre to be treated for mild hypothermia. A hospital spokesperson said they were all in stable condition.

Rowers were out on the water at 5 a.m. and conditions were said to be calm at the time. The high winds came up suddenly and the lake went from glassy calm to 5 foot swells in the darkness. Rowers do not wear life jackets when on the water.

Superintendent Bill Stewart said wind gusts reached 90 km/h.

Eight boys from Westdale secondary school wound up in the water for 20 minutes after their boat capsized. They were rescued, taken to hospital and examined for the possibility of mild hypothermia.

“A gust of wind overturned their rowing shell,” said public school board spokesperson Rob Faulkner. The water was “calm at the start of practice,” he said.

A total of five public schools had teams out on the water, says Faulkner.

Senior students from Hillfield Strathallan College were ordered off the water this morning by the Leander Boat Club, says Hillfield director of operations Chris Kwiecien.

None of their boats capsized and nobody needed medical treatment. The students were taken back to campus and went to class as usual, he said. Their families were contacted and told everyone was safe and sound.

“It was a break of dawn, kind of thing,” when the rowers set out in the early hours, says Kwiecien. The wind picked up after they were on the water, he said.

Pat Daly, chair of the Hamilton-Wentworth Catholic District School Board said a boys’ rowing team from St. Mary’s high school was on the water at 6 a.m. but came off at 7:20 a.m.

“When the wind started to pick up, they returned,” he said.

All those students are safe. He said the girls’ team from St. Mary’s was not rowing today.

A team from Bishop Tonnos high school was also in the water. They came back to shore at 7:20 a.m. One student and one student coach were taken to hospital to be checked out.

Some rowers were carried as far as the opposite shore from the Discovery Center along Hamilton's waterfront.

Frantic parents gathered at a police command post set up at Leander Boat Club.

Environment Canada issued severe wind warnings just before 5 a.m., anticipating wind gusts up to 100 km/h over regions adjacent to Lake Erie and spreading northeast to Lake Ontario midday.