Safe Diving?

[Chris H]

We all talk about it, but what do you consider a "Safe" dive?  Is making it back to the boat enough?  Rule of thirds?  Enough gas for you AND your buddy to surface safely?  Do you start to ascend when it gets hard to breathe and have to pull the lever on the J-Valve?  Do you know what your SAC rate is?  Do you know what SAC rate means?

I have seen reports on other sites of dives to the WB Allen (165’) and other "non-recreational" dives on a single 80, most likely filled with air.    Personally, I think that is far from a safe dive, and an OOA is almost immanent.  How is a dive like this planned? If the fertilizer hits the ventilating system how are you getting back to the boat, your home, and your family?  The only thing a single aluminum 80 should be for on a dive like this is 50% for deco gas, and the Luxfers ride better than a Catalina.