HMCS Algonquin and HMCS Protecteur collided Friday afternoon during a towing exercise they were conducting while en route to Hawaii, the navy said.
Algonquin bore the brunt of the damage, with photos showing a large gash in the hangar along the port, or left, side of the ship. Protecteur fared better, but was also damaged on its front end.
Commodore Bob Auchterlonie, the commander of the navy's Pacific fleet, said the ships were conducting a towing exercise in which Algonquin was to tow Protecteur.
"To be very upfront and candid, something went dramatically wrong, and that's a bit of an understatement," Auchterlonie said in an interview Saturday.
"The ships were conducting a towing exercise, which was a normal part of our routine operations and normal business at sea. ... There is an inherent risk of ships operating together at sea in close proximity, but this sort of incident, I've not come across in my career."
The vessels each had more than 300 crew members on board, said Auchterlonie, though no injuries were reported.
The ships were on a deployment to the Asia-Pacific region, where they were scheduled to attend the International Fleet Review in Australia in early October before conducting a series of diplomatic stops with the Department of Foreign Affairs.
Instead, the ships were ordered to return to Canadian Forces Base Esquimalt, near Victoria, where they were expected to arrive by late Saturday afternoon.
Auchterlonie said the navy will convene a board of inquiry to investigate what caused the collision.
Each ship will also undergo a technical assessment to determine the extent of the damage and the repairs required before returning to service.
"The full impact of the sailing schedule has not yet been determined, but clearly by the extent of the damage on Algonquin, she's not deploying," said Auchterlonie.
"We're looking at options for Protecteur, as well."
Auchterlonie acknowledged even experienced sailors can be rattled by such an incident at sea, and he said their welfare is a priority.
"Both the command teams on board Algonquin and Protecteur are very engaged with their ships' companies, because the first concern we have is for the safety and security of our sailors," he said.
"Thankfully, no one was injured, but this was a significant event, and I'm going to ensure our sailors, when they get back, get the support for me and the entire formation."
Algonquin is an Iroquois-class destroyer built in the early 1970s, according to the Royal Canadian Navy's website.
Protecteur is an auxiliary oil replenishment ship — one of two such vessels in the navy that were launched in 1969.
The Department of Defence is currently considering a plan to build new supply ships to replace Protecteur and its sister ship, HMCS Preserver, which is based in Halifax.
— By James Keller in Vancouver
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