hobodiver
Contributor
I am learning more every second tonight. So eliminating the Nitrogen is mostly about eliminating the nitrogen narcosis, not the deco sickness element, right?
That's one reason. Helium is also much less dense than Nitrogen, so it breaths easier at depth.
There may be other reasons as well.
One of the drawbacks to Helium is that it's expensive. Another reason to use a rebreather.