It's been 10 years since Jean Chretien's Liberal government doled out $900 million to the British in return for four used diesel powered submarines -- today only one is operational, the others dry-docked and will cost taxpayers millions in repairs.

Rob Huebert, associate director at the Centre for Military and Strategic Studies, says the vessels are vital to Canadian sovereignty and in desperate need of maintenance.

According the Huebert, the fleet's current state of disrepair can be attributed to inactivity. He compares the submarines to a car left outside for years without being driven.

"They stayed in water way too long," Huebert told Canada AM on Thursday from Calgary.

Huebert says the British government was intent on selling six submarines to Canada, but the transaction took three years, and in the end only four were bought.

Former Liberal defense minister, David Collenette, has said the delay was due to fear of political backlash.

"Chretien had always been a strong supporter of the submarine proposal, but he worried about the timing of an announcement when so many sectors of Canadian society had borne the brunt of deficit cutting," Collenette told the House of Commons defence committee in 2004.

Eventually, Canada purchased the HMCS Chicoutimi, Corner Brook, Victoria and Windsor -- but they've been plagued with problems.

On its maiden voyage in 2004, fire aboard the HMCS Chicoutimi killed Lieut. Chris Saunders and injured eight others. It is expected to be out of commission until 2012, two years after its initial re-launch date.

Only the HMCS Corner Brook is believed to be cruising the ocean, and the Victoria needs $195 million in repairs if it is expected to be on duty in 2009.

The HMCS Windsor is also undergoing repairs.

"Submarines are incredibility difficult technologies to run," Huebert said, pointing to Russia's beleaguered fleet and an explosion aboard a U.K. vessel off the coast of Alaska in 2007.

"Unfortunately, the technology is not only valid, it is necessary," he added. Huebert cites the Asia-Pacific region as an example the "huge growth" in submarine procurement.

Japan has 14 subs, while China, South Korea and Taiwan are all expanding their fleet.

Once they are operational, the submarines are some of the best, according to Huebert. Diesel-powered subs are slower than nuclear powered vessels but are also harder to detect under water.

Huebert says it's difficult to convince Canadians that submarine capabilities are important to the country's sovereignty. In the Arctic, the mere presence of a Canadian sub means other countries must inform our government of their whereabouts.

"The submarines are very important for underwater surveillance in Canadian waters, particularly in near-ice conditions for our North," he said.