The pool holds 266,000 gallons and is between 10' - 15' deep. The bear, currently the female twin, Anana, has access to her indoor den. Her brother, Lee, came to the zoo w/ stereotypic behavior, which is a hard habit to break. The keepers gave him access to his indoor den which significantly helped in reducing it. The smaller pool, which is to the left in this photo, was filled with wood chips. Anana loves to swim in front of the large viewing window where small children like to stand. This exhibit is nothing like the polar bear exhibit at PZ & A (I haven't been to Detroit yet). But, at one time, it was the largest polar bear pool in North American zoos. LPZ has a separate seal exhibit near the west entrance.
I've never disputed the fact that the pool is of a decent size, and it allows for lots of space for swimming. However, the land area is shockingly small and probably takes the bears a few seconds to cross.
@zoogeek: in reality a thousand times more space than what is shown in this photo. Even some real natural substrate (ie: grass) would go over well with most zoo fans.