http://youtu.be/E2qAj2c3XxI In Batman: Whenever Batman steps to an aquatic foe, like Killer Croc for example, youll see him whip out his re-breather which allows him to breathe underwater (or in noxious gases of course) for a limited time - around 2.5 hours by some accounts. In Reality: Re-breathers, not surprisingly, exist and have existed for years, primarily to aid scuba divers and deep-sea explorers in their underwater pursuits. Of course Batmans own version of the technology has been shrunk to the point that its little more than a mask that fits over the gap left in the cowl. But that doesnt mean you cant own your own real world version, albeit at quite the hefty price. Available from all good scuba stockists, a new rebreather will set you back around £5000. Just dont go picking fights with crocodiles.