While working on a reference article on pressure-depth relationships, I was reminded of divers I had a few years ago. This couple has a creative way of finishing a dive. After maintaining a reasonably well-controlled safety stop, they both reached for their inflator hoses and pffffffffttt held down their inflate buttons and shot to the surface from 15 feet. When I chatted with them about this dangerous habit, they told me that their open water instructor taught them to ascend this way.

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A client came into a friend's dive shop and announced "I want to go dive Cozumel!" This gentleman was not a certified diver. When my friend explained that his dive shop only takes certified divers to Cozumel, the client decided to take the Open Water Diver Course. While a certification course may have been the correct decision for this client, it brings up the question: why are people getting certified? If it is just to say they went diving on a famous reef or to check out some pretty tropical fish once every few years on vacation, certification may not be not the correct decision.

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"Make sure you turn on your oxygen," a scuba diver reminded his son. I understood that the diver simply wanted to make sure that his son had opened his tank valve before gearing up, but hearing someone refer to a recreational scuba tank as containing pure oxygen makes me do a double take. Perhaps the father merely lacked precision of language, but it seemed to me he lacked something more fundamental: understanding. Diving with pure oxygen can kill a diver even at shallow depths. Read more...

A certain kind of diver makes guides groan. This diver assembles his gear, and then reaches for his dive bag and breaks out the accessories. I watch in disbelief as he slides a mesh tank protector over the rental tank, and then proceeds to clip on to his buoyancy compensator large slates, a magnetic etch-a-sketch, dive tables, blinking tank strobe lights, a tank banger, low pressure hose noise maker, a shaker, a camera, a fish ID slate, a flash light, fancy octopus holder, a surface marker buoy without a reel to deploy it, mesh collecting bags (for trash?), and various types of extra clips and hose retractors "just in case". In the dive industry we call this kind of diver a "Christmas tree diver" (CTD) because he has so many doodads hanging off of him that he looks like a well-ornamented Christmas tree. Read more...