Gaz is of course right that dehydration is a major cause of DCI. There are many others, and people who have done everything "by the book" can still get bent, as anyone who attended the lectures would have learned.
I didn't mean to say "a lot" of people use the Chamber, just that more do than some people realise. And as Gaz so rightly says, it is no shame on the diver or the operator if someone needs help from the Chamber. Round the other way, in fact - quite a few people experience minor symptoms of a bend and actively ignore it - it is the wise ones who get themselves checked out. So long as they are insured they are able to do this without fear of major financial consequences.
AmbergrisCaye.com 
