Analysis of rebreather diving incidents shows that full-face masks and mouthpiece retaining straps are effective for protecting the airway if a diver loses consciousness underwater due to breathing an inappropriate gas mixture, the most common disabling agent. This increases the chances of a successful rescue. Full face masks are more effective, bit more complex and expensive. Mouthpiece retaining straps are not as effective but are inexpensive and simple to use. These measures have not been widely adopted by the recreational diving community.
