Choosing Gas

While I was doing my ANDP course I was interested in how the relationship of deco gas O₂ percentage had a non-linear relationship with the time it would take to get to the surface. Naïve me thought that if 50% O₂ got me to the surface in x minutes, then 100% O₂ would get me there in half the time, but that’s super wrong. You can use a leaner mix at a deeper stop, meaning that it’s useful for…