Canada is still months away from having battle-ready submarines on both its West and East coasts, says the navy's commander.

During an exclusive interview with The Canadian Press aboard the navy's only operational submarine — the Halifax-based HMCS Windsor — Vice-Admiral Mark Norman said British Columbia-based HMCS Chicoutimi will be operational by early next year.

Norman said a problem with some of the welding on HMCS Chicoutimi as well as HMCS Victoria was discovered late last year.

He said the welding work was done by a subcontractor that was hired by a contractor working on both Victoria-class submarines as well as some surface ships in Victoria.

The welds were passing inspections, but the navy did not realize at the time that the inspection process itself was flawed, said Norman.

"In this case, we relied on a series of contracted support systems that didn't deliver what we needed from them. So we've tightened up our processes and the good thing is that we found it and we're fixing it," said Norman during an interview aboard HMCS Windsor as it sailed roughly 57 metres below sea level off the coast of Halifax.

"It's important that we learn these lessons, but it's unfortunate that we have to learn them the way we have."

Fixing sub will take months

Norman said a complete audit was conducted and the subcontractor has agreed to fix the roughly 70 problem welds on HMCS Chicoutimi, but that process will take several more months.

He said HMCS Chicoutimi will be fixed first, followed by HMCS Victoria, which is currently being used for training purposes. The navy's fourth sub — HMCS Corner Brook — is undergoing deep maintenance.

Norman said as long as the West Coast is without an operational sub, Canada is letting down its American allies.

"The submarine is an important part of not only the defence of North America, but it's also an integral part of how we work with the United States in everything from training exercises to pre-deployment mission readiness for both their navy and for our navy," said Norman.

"It's an unfortunate and disappointing gap in the capability. But we'll get it back."

Only 1 operational sub

Canada's four long-range, diesel-electric submarines were bought from the Royal Navy in 1998 for $750 million, but the transition to full Canadian Navy operations has not been smooth.

Only one of the subs is operational following years of setbacks, including a fire aboard HMCS Chicoutimi in 2004 that killed Lt. Chris Saunders and sent two others to hospital during its first Canadian voyage.

'A country that has the largest maritime estate in the world ... should have a tool in its toolbox that can declare exclusive control over a piece of water at a time and place of its choosing." - Vice-Admiral Mark Norman

HMCS Corner Brook hit the ocean floor during training exercises off Victoria in June 2011 and will be out of service until at least next year.

Canada spends roughly $200 million a year on maintaining the submarines, said Norman.

But submarines are integral to Canada's navy fleet because they are the "ultimate guarantor of maritime sovereignty," said Norman.

"I would submit that a country that has the largest maritime estate in the world, and that has interests well beyond our borders and our continent, should have a tool in its toolbox that can declare exclusive control over a piece of water at a time and place of its choosing, and that's what a submarine gives you," he said.

"By operating submarines, we're required to share information about submarine locations, positions and movements, and that gives us a degree of insight into what's going on in the waters adjacent to North America, and elsewhere in the Atlantic and Pacific."