If a person sails from Arctic Ocean to the Labrador Peninsula, which bodies of water does she or he cross

It really depends on the time of year and the skill of the Captain.

One could go past the town of Alert and into Baffin Bay. From Baffin Bay, one would head down into the Labrador Sea and towards the Labrador Peninsula.

Or one would go down the Eastern side of Greenland in the Greeland Sea and through the open Atlantic into the Labrador Sea to one's destination on the Labrador Peninsula.