Are Haloclines dangerous?

Question

I think they are called haloclines. I was watching planet earth (series) and they mentioned how they could cause cave divers to become disoriented. The narrator said that it makes some divers think that there isn't water above them, but breathable air. Has anyone ever died from this? Or taken some important piece of equipment off because of this?

Answer 1

A heliocline is where water of differing salinities (saltiness) comes together. The less salty essentially floats on the more salty. This creates the illusion that there is a "surface" there.

To my knowledge this has never resulted in a fatality. This is mainly due to SCUBA divers training, which ensures that they retain the regulator (the thing from which they breathe) in their mouth until they have established positive buoyancy on the surface. You would very soon realise that you were not at the surface if you did this while submerged!

It has, on many occasions resulted in disorientation.

Sorry, no pictures!