Code: 600PK, 600PK-DG, 300PK, 300PK-DG
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 ready to help us. Next time you make a dive count the times your buddy is further than arm's length from you. You will be surprised that they are much further away more often then you may think.