Rescuing an unresponsive diver in overview: buoyancy, ascent, surface, in-water breaths and extrication. Orientation only, practice belongs in a rescue course.
What does rescuing an unresponsive diver look like in overview? The honest answer: prepare the ascent, bring the diver to the surface, decide quickly there whether rescue breaths are needed, and get to land or a boat as fast as possible. This is an overview, not a manual. You learn the practice in a rescue course, not from a text.
Why overview instead of instructions? Rescue is among the things that can go wrong with good intentions. The Diving Committee of the Undersea and Hyperbaric Medical Society (UHMS) divided the rescue into three phases: prepare for ascent, retrieve to the surface, care at the surface. Open questions include how fast to ascend, whether effective in-water breaths are possible and when they take priority over quick extrication [2]. The Divers Alert Network (DAN) summarizes it in practice: the rescuer needs formal diver-rescue training and experience; he may prioritize his own safety [1].
A look at practice shows why training matters: in an analysis of Australian dive fatalities there were often considerable delays in recognizing, rescuing and recovering an unconscious diver, and thus in starting resuscitation [5]. This guide explains and motivates, it does not replace the rescue course.
An unconscious diver does not respond, is limp, not breathing or breathing poorly. Have help alerted immediately. Milestone (course): you recognize the situation and alert in under ten seconds (rule of thumb).
First check: is the regulator in the mouth? Is the diver convulsing? [1]. Then establish buoyancy. Do not decide by feel alone but by your training. Milestone (course): you establish buoyancy without rising uncontrolled yourself.
On ascent rate the committee says: ideal for the victim would be "as fast as possible", but the rescuer's own safety limits it. If the rescuer has a decompression obligation, a direct ascent can be dangerous; then he makes the victim positively buoyant and lets him rise alone [1]. The source gives no concrete values, and we give none: that belongs in your course.
Once the diver is at the surface and positively buoyant, the rescuer quickly checks whether rescue breaths are needed and works toward a fast extrication [1]. The committee notes: respiratory arrest in a dive accident is likely due to lack of oxygen, and breaths may prevent progression to cardiac arrest [1].
DAN writes: in-water breaths should only be given by trained rescuers in safe conditions such as calm water without waves; opening the airway in water can allow additional water in [4]. Up to 49 percent better survival is described for breaths that interrupt the drowning process [4]. An in-water breath is therefore a decision, not a reflex. DAN also advises: chest compressions in the water are ineffective and only delay extrication [3].
Once the diver lies on stable ground, you start rescue breathing and chest compressions and give oxygen, with the DAN mask at a minimum of 15 litres per minute [3]. If he is unconscious but breathing, you place him in the recovery position [3].
Prevention beats rescue. A good buddy check, suitable gas reserves and a plan lower the probability that you will ever have to rescue. And if you wonder how seriously to take training: schedule a rescue drill once a year with your dive partner, with real equipment. Repetition keeps reactions fast [4].
In overview: prepare the ascent, bring the diver to the surface positively buoyant, assess quickly whether breaths are needed and get to land or a boat as fast as possible. The practice belongs in a rescue course [1].
Only if you are trained and conditions are calm [4]. Opening the airway in the water can let water in. If land or a boat is near, quick extrication takes priority [3].
No. DAN says they are ineffective in the water and delay extrication [3]. They start on stable ground.
At least once a year. First-aid skills can fade after around six months without practice [4].
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