In a summer of record marine traffic in the Arctic, the Canadian military is about to begin a series of elaborate rehearsals in case something went wrong on any of the increasing number of cruise ships, pleasure craft, research or commercial vessels plying the unpredictable waters of the North.

"With climate change and the opening of the Northwest Passage, we're seeing increases in all those areas," said Brig-Gen. David Millar, commander of Joint Task Force North.

"Our scenarios are focused on the types of marine disasters that could potentially happen with a sharp increase in naval activity in the North."

Beginning Tuesday, the army, navy and air force will begin Operation Nanook 08, the latest in a series of manoeuvres designed to boost Canada's Arctic sovereignty and increase the military's ability to respond to emergencies.

The exercise will involve 120 regular soldiers and about 70 Canadian Rangers, the largely aboriginal reserve force that acts as the army's eyes and ears in the North. Two warships will be deployed, including the frigate HMCS Toronto, as well as air force Twin Otters and Aurora surveillance planes.

A record number of civilian agencies will also take part, including the Canadian Security Intelligence Service and the Canadian Border Services Agency.

Defence Minister Peter MacKay and Chief of Defence Staff Walt Natynczyk will also observe the exercise as part of a northern trip to see Canadian Forces efforts in the region first-hand.

Operation Nanook will simulate an outbreak of disease on a cruise ship, a hostage-taking on a cruise ship, a fuel spill and a fire on a Russian cargo ship.

"When we starting planning for the exercise, it was the other government departments that came to us and said 'These are the types scenarios we'd like to be able to exercise,' " said Millar, who took command of the northern forces on June 13.

A total of 26 commercial cruises are planned in the Canadian Arctic this season, an all-time high and an increase of four trips over last summer. As well, at least eight private vessels are thought to be sailing in and around the Northwest Passage.

The passage itself is expected to soon be ice-free for only the second time in recorded history. The first time was last year.

Military and civilian experts have long warned that some sort of maritime disaster is only a matter of time in the Arctic. There have been three accidents involving cruise ships - including one sinking - in the Antarctic in the last two years.

This operation will concentrate in the south Baffin area.

Ships will patrol the Hudson and Davis Straits. The soldiers will be deployed to the communities of Kimmirut and Pangnirtung, where local Rangers will train them in fine points of Arctic survival, such as spear-fishing.

Aircraft will patrol the skies to monitor who's doing what in the waters Canada claims as its own.

Although drifting ice has been unusually heavy in the region this summer - blocking cruise ships from visiting some communities - Millar said that shouldn't prevent the naval ships from operating.

Operation Nanook 08 will run until Aug. 26. Including this one, the Canadian military has conducted at least 18 major operations in the Arctic since 2002. They have taken place from the Beaufort Sea in the west, to the Mackenzie Valley in the Northwest Territories, to Hudson Bay, to the High Arctic shores of Ellesmere Island.

Some operations involve epic snowmobile patrols across thousands of kilometres of some of the most forbidding terrain on the planet. Some have simulated airplane crashes or terrorist attacks on energy infrastructure. Soldiers and sailors have gone after mock smugglers and illegal fishers.

More and more government departments have become involved with such operations over the years. Operation Nanook will involve the Coast Guard, the RCMP, CSIS, Border Services, Public Health Agency Canada, Health Canada, Public Safety Canada and Transport Canada, as well as Nunavut health and emergency measures organizations.