The Vancouver Coast Guard acted as impromptu whale watchers Thursday morning as officers hit the narrow waterway of False Creek in search of a wandering whale that spent the afternoon in the area yesterday.

The big grey whale was first sighted in the high-traffic channel in downtown Vancouver Wednesday around noon but by sundown coast guard and fisheries officials were confident they had pushed it out to English Bay and into open seas.

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But several sightings were reported by residents later that evening and early Thursday morning near Jericho Beach and English Bay.

The Vancouver Police Department's Marine Squad launched several Zodiak boats to provide transport to scientists and aquarium staff and provide enforcement. The waterway is frequently traversed by small ferries from Granville Island to Yaletown and English Bay, as well as boaters and kayakers.

Officials have yet to officially confirm the sightings.

The rare sight of the whale is drawing enthusiastic crowds to the city's seawall and shoreline, with spectators racing to catch a glimpse of the giant mammal.

Grey whales are currently migrating up the British Columbian coastline from Mexico to the Bering Sea to feed for the summer.

Dr. Andrew Trites of The University of British Columbia's Marine Mammal Research Unit said the mammal was likely sidetracked on its way up north.

"They may be a little bit hungry and don't have the same energy," he said.

"They need to get energy from somewhere so they're exploring some of these inside waters."

Researchers from the Vancouver Aquarium are keeping close tabs on the whale's movements and say it doesn't appear the whale was feeding in False Creek. Grey whales collect food in shallow bays, where they scoop up mud to filter out krill and other small creatures.

"You can often see a bit of a plume of sand when they are feeding and they're flipping onto one side. This one just appeared to be travelling," said Meghan McKillop, a research assistant at the facility's Cetacean Research Lab.

McKillop said the whale was acting very low key.

"[It] is to be expected because it was in a very heavily populated area with people and boats. So it was just taking very long dives, about five minutes or more between dives."

A grey whale was also recently spotted in Howe Sound near Squamish, about halfway to the resort city of Whistler.

Last month, five grey whales turned up dead along the shores of Washington State and Vancouver Island. So far -- scientists can't pinpoint a reason.

With a report from CTV British Columbia's Maria Weisgarber