To be safe, solo divers must be self-sufficient, well trained, prepared, practiced and prudent. They should have a completely redundant set of all life support equipment – a complete, self-contained backup breathing gas supply sufficient to return to the surface from any point of the planned dive profile. In addition, the responsible solo divers adhere to a very conservative dive profile, both in depth and level of difficulty. Unlike the buddy system, which encourages divers to rely on others in the event of an emergency, solo diving encourages divers to prepare themselves to overcome emergencies by their own means. The divers who engage in solo diving are typically those who are experienced and equipped enough to handle problems themselves. Solo divers must feel comfortable and relaxed in doing this sort of diving, and nobody should ever think of doing diving solo if they are not both competent and comfortable in doing so.