The closest I've been to a Polar Bear is from behind a glass window at the Toronto Zoo.  I'm going to assume you're in the same boat.  Mark Dumas swims with an 800 pound polar bear...among other things.  He lives in Abbotsford, B.C., where he trains animals to be in movies and television.  You may recognize this polar bear from the movie "Alaska" (I don't). 

Mark has been working with Agee ever since she was a cub.  16 years later, they seem to have a great relationship.  It's important to point out that owning exotic animals can be dangerous, but Mark believes that his experience has taught him to interact with the animal. 

By the way...Agee is the only trained polar bear in North America.