On 2 Mar 13 I was involved in a rescue training weekend organised by members of GUE-UK and supported by Aquanauts Dive Centre in Plymouth with a view to increasing our rescue skills and putting those that we had into practice in a representative environment. This included unconscious casualty lifts, surface rescue including cutting a casualty out of the their harness and getting them on a hard-boat, CPR and defib training – including whilst underway at high speed and finally some basic sea survival skills including signal flare deployments. I then gave a presentation on potential ways to improve diving safety, my DISMS work and also where my PhD is going.
The day went extremely well with many salient lessons learned, the most pertinent being that recovering an unconscious diver from depth is not an easy task and anything you can do to prevent the need to do so should be at the forefront of your dive planning. This article will cover the major lessons learned.
The day was cold with air temps of around 3-5C, water temps 7C, a slight breeze and calm seas. Ideal really to bring out the challenges of cold water diving without making everyone sick on an unstable platform. The cold water meant that the majority of people were wearing dry gloves and I wanted to make sure that people could use cutting tools in the water so volunteered to have my harness cut off me during my rescue. This provided to be invaluable as it was apparent that the Trilobite cutting device has a very small window of effectiveness when it comes to angles of placement. If the blade is not perpendicular to the webbing and the device parallel to the surface, it will not cut. However, if it is, then the webbing is cut extremely easily and falls away.
During one of the rescues, a diver in a drysuit but without gloves jumped in to help rescue a casualty on the surface. Within a few minutes he had lost the effective use of his hands for fine motor skills. If you are getting in the water to help, make sure you have adequate thermal protection to cover your duration in the water.
Unconscious Diver Lift
This is hard if you haven’t practiced it. You WILL use more gas than you think you will which means you have to have good situational awareness of your gas consumption. The scenario we practiced this lift in did not tax this SA requirement as we were in 12m with twin 12s containing 200bar of 32%. At one point I really noticed that I was over breathing and had to calm down, my buddy during his rescue drill had to take a time out for 90-120secs as he was struggling so much to get me in the correct orientation when I was his casualty. His problem was that I was playing the very relaxed diver in which the natural position is feet up, head on the bottom. This position also gave me a problem as Apeks regulators have a slightly wet breathe when upside down and I could feel sea water collecting in the roof of my mouth but no effective way of expelling it. Once the diver is in the correct orientation, the traverse is relatively easy with the rescuer reaching around to hold the casualties head up with the right hand and controlling rescue team’s buoyancy by using the casualty’s wing inflate and kidney dump with the left hand.
Speed is of the essence in any rescue but you need to be a relatively stable platform before you move off otherwise there will be problems later. During the ascent you need to be controlling four sets of buoyancy (2 x wings, 2 x drysuits) and the last 5m or so are the hardest because of the expansion rates involved. Do not be surprised if you lose it in the last 2-3m of ascent.
When conducting the rescue, you need to be cognisant that a diver may be unconscious due to the being OOG which means that they will not have any gas in the wing to lift you and them. You may have to use their drysuit or you may have to control the rescue team buoyancy using your wing. If the latter, be aware that they will be negative and as such you need to keep very positive control of the casualty.
A couple of scenarios were run, the first was 2 rescuers in the water and they would cut the casualty out of their harness (me) and the bring them onto the lift. As described above, make sure you know how your cutting devices work and you have practiced using them in a representative environment; this is not bare handed on the kitchen table in the warm! Cut both shoulder straps off and either cut the waist belt or unthread it. Make sure the wing is inflated as the equipment may be required for any subsequent investigation. As soon as the regulator is removed from the casualty, the ‘head man’ takes control and stabilises the head, maintaining the airway from that point to the handover on the boat. Direct everything and keep the mouth/nose clear of the water.
The second scenario was run as if the rescuer and casualty were the first pair up and no-one else to help on the surface; they also hoped to remove the kit rather than cut it off, and we showed that removing a harness and kit is a real hassle and that it should be cut straight off.
In both cases the rescuer entered the lift backwards towing the casualty and directed the skipper to raise the lift. When level with the deck, the casualty was ‘dragged’ over the top of the rescuer whilst they lay flat and CPR was effected on the hard boat deck. The ease with which the casualty was taken over the top of the rescuer was dependent on the relative sizes; small casualty over large rescuer was much easier than the other way around.
More on the surface side of the house in the next blog entry. However, the key message is that underwater rescues are hard, and they are all different because of the situation you are going to be in. Everything will not go to plan, so be flexible and accept that you might ‘cut corners’ to expedite the recovery. Time underwater is wasted time when trying to save someone’s life, but don’t become a casualty yourself.