With an equal mixture of excitement and trepidation -- and a final, furtive scan of the horizon for polar bears -- I drop over the side of the boat, into the icy Arctic waters of Hudson Bay. As I hit the water, my breathing is reduced to shallow, frenetic gulps inhaled through my snorkel. I'm decked out from head to toe in an Arctic rated dry suit, yet I'm not completely adapted to this aqueous otherworld.
 
I bob just below the water's surface -- balancing by my ankles on a tow line -- as the boat driver trolls me and my snorkelling buddy through Hudson Bay, like bait on a line... In the distance, I can see the town of Churchill, Manitoba, which is comforting."Belugas at three o'clock and moving quickly," shouts our driver, as I replay the advice from Brian Sheehan, curator of marine mammals for the Vancouver Aquarium, who told me how to identify "happy" versus "agitated" beluga behaviour. When a beluga contorts its body into a C-shaped pretzel, said Sheehan, watch out. MORE>>>>

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