From what I understand, the water has 800 pounds of salt so you can float with no effort. Then the water is heated to something like 93.5 degrees which is the temperature of the surface of your skin so your body can't tell the difference between what's above and below water. While you're floating, your ears are under water so you can't hear anything and the tank is pitch black so you can't see anything either.

Pretty intense but if you could handle it, sounds cool.

Somebody mentioned Joe Rogan. He's actually giving away an isolation tank. He got a new one and he's giving away his old one. Paying for shipping, installation and everything. Cool guy. joerogan.net if anyone's interested.