For the first time, Ottawa is trying to find a sunken 19th-century ship that helped discover the final leg of the Northwest Passage.

In January 1850, the HMS Investigator set sail from Britain under the command of Capt. Robert McClure.

He was on a mission to rescue Sir John Franklin, a renowned British explorer whose recent 129-man expedition had vanished while searching for a potentially lucrative trade route to connect the Atlantic and Pacific Oceans.

The Investigator entered Arctic waters from the west after travelling around the southern tip of South America. Like Franklin's expedition, the ship then became trapped in ice and the crew was forced to eventually abandon it. (The expedition was later miraculously rescued.)

McClure never discovered what befell Franklin, but he was credited with stumbling on the last uncharted section of the Northwest Passage -- which by then had eluded British explorers for 300 years.

Now, archaeologists with the federal government are trying to locate the historical vessel. It's believed to have sunk near the western edge of the Canadian Arctic archipelago.

McClure's expedition "kind of had a domino effect on the whole thing," said Marc-Andre Bernier, who is in charge of the Parks Canada archeologists seeking to uncover the Investigator's resting place.

On Thursday, the team arrived at a cache of supplies that McClure had deposited on the shore of what he dubbed Mercy Bay.

They set up a camp that includes an electric fence and is watched over by Inuvialuit wildlife monitors to protect them from roaming polar bears.

A few hundred metres off shore, the archeologists then set about mapping the seabed using side-scan sonar. If they find anything unusual or "shipwreck-like," they'll dispatch a miniature robotic submarine with a camera attached to verify the find.

"Cold water is very good for preservation," Bernier said by phone from Ottawa. "If the water is fairly deep, then we might have some fairly intact structure."

"There are other instances of wrecks found in the arctic in fairly good condition," he added.

Due to the remoteness of the site, which lies in what is now Aulavik National Park on Banks Island, the archeologists have no means of communication save for a satellite phone to be used only in case of emergencies. So news of their discoveries won't be known until early August when they return to the mainland.

Another trip is planned later in August to locate Franklin's two lost ships -- both of which have been deemed National Historic sites -- off the coast of Nunavut.

Bernier said the timing of the searches has to do with the opening up of the Northwest Passage.

"There are a number of sites in the Arctic like this," he said. "We want to make sure they're protected."

"There's more water free of ice every year… There are more visitors in the Arctic. There's more boat traffic."