You can provide open-water rescue breathing in two ways: mouth-to-mouth or mouth-to-mask. Mouth-to-mask refers to rescue breathing using a resuscitation mask or similar barrier device. In today’s society, with the increased concern about the transmission of various diseases, giving rescue breaths with some sort of barrier device is highly recommended. Obviously, mouth-to-mouth rescue breathing carries the risk of contact with another diver’s bodily fluids, not to mention having to deal with vomitus, which occurs regularly in a diving or submersion incident scenario. Mouth-to-mask rescue breathing may also make it easier to get a good seal and control a diver’s airway, especially in open water. The choice of which type of rescue breathing to attempt should be made before you even get in the water. If you plan to use a mask, you will need to make sure you have one with you and that it is prepared for use.
Having a barrier device such as a resuscitation mask available in a diving rescue scenario may not always be an option, however. Even if you keep one in your BCD pocket, it has to be accessible; and unless you’ve been meticulous about caring for the mask, it may not be usable when the time comes. One problem with keeping a resuscitation mask in your BCD pocket is the fact that it has a positively buoyant, inflated cuff. Divers have been known to reach into their pockets and find that their masks have floated away.
To perform either version of open-water rescue breathing, you need thorough training and frequent practice. In general, the techniques for delivering rescue breaths are the same for both, so we will describe mouth-to-mask rescue breathing. Where appropriate, we will highlight the differences between the two techniques. To begin, with your thumb and forefingers in the shape of a C, seal the resuscitation mask to the diver’s face, covering her mouth and nose (see figure 8.3). You will need to press down firmly to completely seal the resuscitation mask to the diver’s face.