Care For A Swim?

I have a number of blogs I frequent on a daily basis. One of which is a blog called "Cool Things In Random Places". Today's post was about the world's largest pool. In Chile, over 1,000 yards long and over 100 feet deep it's quite the sight. They rent out boats and kayaks for you to get around. If you check out the pics, one thing might jump out at you... It's build on the beach. In fact, the water that is used to fill the pool is sucked out of the ocean, just a feet feet away. Why not just go swim in the ocean?