The pool is decently deep, with the water line being well over 6 feet. I would estimate somewhere around 7 or 8 feet. The size of the pool, however, is extremely lacking for a largely aquatic mammal the size of a small car.
I found an article stating that this pool is 12 feet deep (perhaps that is the size of the viewing window) and that the second pool is 4 feet deep. There is only 50,000 gallons of water in Polar Bear Point, which puts it in line with Henry Vilas Zoo's new exhibit (46,500 gallons) but is a huge disappointment in comparison to other polar bear pools in American zoos. Saint Louis Zoo is, in my opinion, one of the top 3 zoos in the USA and so perhaps better things were expected of this expensive new exhibit.
A brief sampling of polar bear pools:
Detroit Zoo = 200,000 gallons (170,000 pool and a 30,000 pool)
Columbus Zoo = 167,000
Pittsburgh Zoo = 150,000
Kansas City Zoo = 140,000
San Diego Zoo = 130,000
Toledo Zoo = 90,000
Louisville Zoo = 88,000
Saint Louis Zoo = 50,000
Henry Vilas Zoo = 46,500
Quality wise I'd say this exhibit is slightly above average even though without question below what I expect from the Saint Louis. To me the two best polar bear exhibits are Detroit and Columbus with North Carolina, Toronto, San Diego and Hogle a bit behind.
I found an article stating that this pool is 12 feet deep (perhaps that is the size of the viewing window) and that the second pool is 4 feet deep. There is only 50,000 gallons of water in Polar Bear Point, which puts it in line with Henry Vilas Zoo's new exhibit (46,500 gallons) but is a huge disappointment in comparison to other polar bear pools in American zoos. Saint Louis Zoo is, in my opinion, one of the top 3 zoos in the USA and so perhaps better things were expected of this expensive new exhibit.
I looked back at the picture of the other pool and it does seem to be 4 feet deep. I feel like 12 feet is an overestimate for this pool, but I didn't really pay attention to the depth when I was there. It's entirely possible that I misjudged it.
I think that the new exhibit was a significant improvement and has a lot of upsides, but it was a letdown compared to SLZ's other achievements, which have otherwise mostly been fantastic.
The online article says that the exhibit was designed to accommodate up to five bears: an adult pair and three cubs. It looks pretty cramped for that many animals, but they're the experts.