Join the dark side, a popular diving phun referring to the dark side of the force in the Star Wars universe, riddled with mystique, black uniforms, supernatural powers (used for evil of course).
Most people have heard of Star Wars or it's iconic villain Darth Vader, if you haven't you probably don't have internet and live in a hut. Vader like other users of the dark side of the 'force' once good, and tempted by the power of the dark side are now ruled by it.
Just a harmless bit of Diving fun right?
Yeah sure, it is, and let's face it, it's pretty fooking cool!
However it can re enforce a problem we are seeing in technical and especially Rebreather diving.