Buddy system
In the Buddy System two or more SCUBA divers dive togther and in co-operation with each other, so that they can help or rescue each other in the event of an emergency. Its a safety system that improves the divers' chances of avoiding or surviving accidents in or underwater.
The system is likely to be effective in mitigating out-of-air emergencies and entrappment in ropes or nets. When used with the buddy check it can help avoid equipment ommission, misuse and failure.
In buddy diving each of the divers is presumed to have a rsponsibility to the other. The "buddies" are expected to monitor each other, to stay close enough together to be able to help in an emergency, to behave safely and to follow the plan agreed by the pair. Most failures in the buddy system occur when one of the divers does not live up to his or her responsibilities as a buddy.
Both alternatives to the Buddy System, solo diving or diving as an individual in a large group, have disadvantages. Although solo diving is used by some divers in technical diving, it means that the diver must be totally self-sufficient in order to survive. In many reported deep diving accidents the diver was solo. In group diving, especially in large groups, poor vizibility or currents, individual divers can easily become detached from the group and lose the protection of any experienced divers in the group. A pair of divers is the best combination in buddy diving: with threesomes, one of the divers easily loses the attention of the other two.
In computing, buddy system is often used as a synonym for buddy memory allocation.