HALIFAX -- The federal government's decision to spend up to $488 million for the construction of new coast guard vessels takes care of an "urgent" need to replace the agency's aging fleet of smaller boats, says an expert.

Defence Minister Peter MacKay announced Wednesday that Ottawa will fund construction of 18 to 21 new vessels of varying types as part of the national shipbuilding procurement strategy.

Although its only a tiny slice of the $33-billion strategy, the replacements are badly needed and long overdue, said Ken Hansen, a resident research fellow at Dalhousie University's centre for foreign policy studies in Halifax.

"The focus over recent years has been on the big ticket items," Hansen said in an interview, mentioning Arctic patrol vessels as an example. "But the small vessels are in equally dire need of replacement. ... The need was extreme, urgent."

Hansen said the coast guard's current vessels, some of which have an average age of 33 years at sea, are unreliable and costly to repair.

The new boats will be used for a range of purposes, such as search and rescue, marine and fishery research, conservation and for protection patrols and navigation, the Department of Fisheries and Oceans said.

MacKay said the vessels will be available for competitive bids by Canadian shipyards that were not selected to build vessels as part of the shipbuilding procurement strategy. Shipyards in Halifax and Vancouver were the successful bidders to build the next generation of navy ships.

MacKay said the program for coast guard vessels will boosts jobs at small- and medium-sized shipyards across the country.

"Shipyards that really weren't in a position to bid for the larger work, that is the vessels for the Canadian Forces, the navy and the ice breaker, this brings them into the national shipbuilding procurement strategy," said MacKay.

The Canadian Coast Guard's fleet has needed updating for more than a decade, and it will likely be at least another decade before the boats cut through Canadian waters, despite Ottawa's prediction that they will be built over the next seven years, said Hansen.

"That is probably optimistic," said Hansen. "There will be requests for bids, then there will be the design process and contract awards. It takes time. These things will not happen overnight."

But the alternative, buying foreign vessels, would strip Canadian shipyards of the work, he said, and would make the project more logistically complicated when the new boats need repairs.

"This is definitely a good news story for Canadian shipyards, it's just going to take some time before the effects of it trickle down and you see people being employed and ships being built."

Replacing the coast guard's smaller vessels is not a particularly politically charged issue and as a result, it has been pushed aside over the years by the federal government, said Hansen.

"If we get a new government, this could be a pipe dream still because it won't resonate politically with whatever party takes over," he said.

"But the clock keeps ticking and the clock doesn't respect federal spending plans."