"To be where no other man has explored before is the ultimate"
The words above were spoken by a cave diver named Dave Shaw who sadly died in January of 2005 while retrieving another diver who had died ten years earlier. (There is a very interesting story attached to that tragedy called "Ghosts of the Abyss" which you will find online).
Deep cave diving attracts a great variation of people from the studious speleologists to the reckless thrill seekers. Many brilliant, successful and intrepid people have been drawn to this sport and to the lure of the unexplored and magical underwater world.
Very risky though and ranked in the world's most dangerous sports. Most of the deaths are attributed to, either inadequate training or inadequate equipment and the remainder stay unexplained.
Definitely an extreme sport where you may reap the ultimate rewards but also pay the ultimate price.
Not for the faint of heart (like me).