In technical diving activities such as cave diving, threesomes are considered an acceptable practice. This is usually referred to as team diving to distinguish it from buddy diving in pairs. Diving in a three person team requires a higher level of situation awareness regarding the disposition of team members, but also provides a considerably enhanced support system if anything goes wrong. As a way to reduce peer pressure on the least confident or experienced diver, some certification organisations suggest making that diver the executive leader of the team, with primary responsibility for decisions regarding terminating the dive or venturing into areas of increased difficulty or risk, while retaining the general rule that any diver can terminate the dive at any time without argument. When professional divers dive as buddy pairs their responsibility to each other is specified as part of the standard operating procedures, code of practice, or governing legislation. This may range from equal mutual support to one of the divers being appointed as the safety diver, with no task responsibilities, to the task specialist. Support divers A technical diving support team is a group of people organised to provide support to the divers in a similar way to a professional diving team, but without the same legal constraints. Support divers are recreational divers who are members of the support team who have made themselves available to provide in-water assistance to the primary diving team, and are typically used for a particularly complex or hazardous dive, such as in depth record attempts and major cave and wreck explorations, where the lead divers may need to spend several hours under the water, and the dive is logistically complicated. They may be chosen for useful support skills other than diving, but must be competent for the dives they are expected to do. Such support may include deploying and recovering stage cylinders, monitoring and escorting the primary team divers during decompression, providing additional breathing gas when requested, and providing assistance in an emergency. In some cases they may function as standby divers, and not be required to enter the water during the dive unless something goes wrong. Personal protective equipment for mitigation 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