anyone tried floating in a flotation tank? what is it like?

how does it differ from floating in a swimming pool or bath?
Flotation tank is (ideally) a lightless, soundproof tank in which subjects float in salty water (denser than the Human body) at Skin temperature. Such tanks are now also used for meditation, prayer, relaxation, and in alternative medicine.

Floatation has many physical and mental benefits because it provides an unparalleled level of relaxation. With the elimination of external stimuli relaxation is promoted. The healing of old wounds and injuries may be aided This deep level of relaxation also benefits the cardiovascular system. Known as the vasodilatory effect, the body's circulation is increased while the Blood pressure and Heart rate are reduced. Furthermore, the effect of floatation on the body allows muscles and joints to release tension and heal more rapidly. For this reason, people suffering from musculoskeletal and rheumatic conditions greatly benefit from Floatation REST, as can Women throughout the length of their pregnancy.
http://en.wikipedia.org/wiki/isolation_t...