Friends and Family

[AandA]

Okay. Let's try this again. You can call it "Scuba 101" or "Physics 101." The problem with allowing the uninitiated access to scuba gear, even in shallow water, is one of basic physics. One of the first things taught by instructors to potential divers is the importance of never holding your breath. The reason for this, when breathing compressed gases under pressure, is that as one rises through water the gases expand. We all remember Boyle's Law. We all remember the concept that 33' of water pressure is double the pressure of sea level. That's only 33'. But heck we're not talking about allowing family or friends to go 33'. We're only talking about allowing them to go 5' or 10' or 12'. The deeper you go, the less dramatic the pressure differential becomes. It is in that 1st 33' of water that the pressure differential is the most significant. The volume of air from 33' doubles when it comes to the surface. Simple math. 33 divided by 2 is roughly 16' where the air expands by 50%. Or at 8' it expands by 25% to the surface. This is MORE than sufficient to burst the alveoli in the lungs causing a significant embolism. Shallow water diving without professional instruction is dangerous! There's not a lot more to say. All it takes is any one of a number of things to panic an inexperienced individual sending them to the surface from a shallow depth with their lungs full of compressed air to cause a significant injury. I would advise anyone interested, once again, NEVER to allow individuals without training use of scuba gear no matter what the depth.

For some more detailed information, any type of a web search can get you information on diving related barotrauma. Here is one: