This picture of the NBL just doesn't do it justice. The Neutral Bouyancy Lab is enormous! 200 ft long, 100 ft wide, and 40 ft deep, with some of the bluest (?) water I've ever seen. The plumbing to pump the water has to be 3 feet in diameter... It's a very impressive structure.
Overall, the pool is configured in two halves. One side has a shuttle mock-up, the other has a space station mock-up. They can run two different training groups at a time, each complete with its own monitoring and support system.
During my time at JSC, I was only able to walk around the observation deck, which is where, I believe, this picture was taken from. Rumor has it that a Russian General returned from a lunch meeting with some NASA folks. Upon seeing the pool he immediately jumped in, complete with his general uniform and associated pins! They're now a little more cautious as to who gets a tour from the deck.
Here's a link to
NASA's NBL Site.
BEN