Researchers currently aboard the Canadian Coast Guard ship Amundsen are slowly mapping parts of the Northwest Passage beyond established shipping routes, but they say it could take years before their data gets added to official navigational charts of the passage.

While aboard the research icebreaker near Clyde River, Nunavut, Jonathan Beaudoin and his colleagues with the Ocean Mapping Group at the University of New Brunswick have been using sonars on the ship to provide  what he called a "real-time view" of the sea floor.

"The shipping lanes are very well sounded, but if you go off that beaten path, there's an awful lot of surprises in Hudson Bay and in the [Northwest] Passage as well," Beaudoin told CBC News.

"So it's good that we're getting off the beaten path. We're slowly filling up the charts."

Beaudoin's group has made several trips along the passage in recent years, mapping areas slightly off the beaten track each time.

"We've found some interesting things that might have turned into a problem had we not gone and sounded them; if a ship had to deviate off the shipping route, for example," he said.

"We found little shoals that haven't been caught before, but we've mapped them."

Some of the mapping information to date is available on the group's website, Beaudoin said. But before such data can be added to official maps, he said the Canadian Hydrographic Service has to conduct more extensive work.

Amundsen captain Stephane Julien said the federal service may decide to add a few soundings for problem areas, but he doesn't think it will do much beyond that for now.

"It's been done in the last 20 years, intensely by CHS [Canadian Hydrographic Service] and Coast Guard ships," he said. "So it is well charted, the passage itself."

Julien said it's costly to create charts in the Arctic. Given the low volume of traffic through the Northwest Passage, Julien said that for now, ships should stick to the established paths.