Having a safety back-up air supply has many advantages over a standard alternate air source. The most obvious is that it is a separate air supply and allows self rescue in an emergency out of air situation. We are taught to stay with our buddy so that in case of an emergency they are right there rea...

"The purpose of this field manual is to provide a standardized source document for Army-wide reference on 'map reading' and 'land navigation'. This manual applies to every soldier in the Army regardless of service branch, MOS, or rank. This manual also contains both doctrine and training guidance on...