By: Paul Hasenmeier
Several years back I was on a dive call where we arrived within minutes and within minutes after arrival we were down an anchor line from a boat with witnesses of where a victim went down. The scene was at the mouth of a river, chaotic by-stander scene on shore, boater traffic that needed restricted, and zero visibility water. Even with a bunch of training this scenario is low frequency / high risk.
As I swam a half-moon pattern off a stationary pivot diver at the anchor all was good for a while and in my mind I thought we are going to find the victim quickly. It’s been a habit when diving for me to swim with my eyes closed in zero visibility environments. Mentally, it takes trying to see out of the mix and allows for greater concentration on search technique. Somewhere around 15 minutes into the dive (I can’t remember exact times now), I felt my tether line take a goofy angle from where it should have been. I stopped and gave one tug on the rope (OK) with no response from the pivot diver. Long story short, I began to coil the rope and swim back towards the tension. The rope had become entangled on a submerged tree. It took me several minutes to untangle the rope in zero visibility and get back to the pivot diver. We then aborted the dive and surfaced. Another set of divers that based their search pattern off the pier found the victim within a couple more passes of our pattern should it not have been aborted.
Since then we have improved our underwater communication capabilities from line tug signals to wireless diver to diver to shore and hardwired systems. Additionally, we have trained with the devils triangle prop in the pool to prepare for underwater entanglements. Similar to the firefighter survival entanglement props you have done, this one is underwater and adds stress in a training environment to prepare for the a situation none of us want to be in.
In the videos below you will get a look at the devils triangle we built. It is secured to concrete weights on the pool bottom. To start, the diver gets through the wire mess with full visibility. Next, the diver lays in the triangle and safety divers tie wires and/or rope to several locations on the diver with full visibility. Lastly, the scenario is repeated with obscured visibility. A minimum of two safety divers are in place with trauma shears and knives during all scenarios should the entrapped diver become distressed. Diver to diver to shore comm systems are also utilized.
DEVILS TRIANGLE SET-UP
DEVILS TRIANGLE SELF-EXTRICATION
We first read about the devils triangle in Kevin Erskine’s book Devil’s Triangle – A Guide To Drownproofing Divers.
Videos by FF Buchanan using the Fire Cam.
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