Anatomy of a Free Flow

It's a common sight. A diver is about to enter the water when suddenly his octopus or even his primary second-stage suddenly does an impression of a jet engine at the end of a runway just prior to take-off. The sudden roar as gas at 1000 psi of pressure rushes out uncontrollably often precipitates the diver to grab the offending item and shake it violently, or even frantically smack it on something hard. All he needs to do is put his thumb over the mouthpiece , but instead, he usually hastily fumbles with the tank valve to solve the problem, even if it means a substantial part of the tank-fill is lost.

Another more serious situation can arise if a secondstage suddenly starts to free-flow during a dive. This is usually associated with icing of the regulator during a dive in cold freshwater. (Seawater around most coasts rarely gets cold enough.) If the water is less than 50 degrees, there is a risk of freezing, so this can happen at many freshwater sites at almost any time of the year.

For a competent diver, this should represent nothing more than an inconvenience. On the other hand, this often results in a fast or uncontrolled ascent, with all the hazards to health implicated in such an action. But there should be no reason for a diver so affected to panic . . .

To read the rest of John Bantin's story about how divers can keep control during a free-flow situation, click here to go to our blog page, www.undercurrent.org/blog, then click on "Anatomy of a Free Flow."