I don't spend my whole dive at 1.6 - but I plan my dive so that I'm not going to exceed it. If I know the sand to be at 132' I'd probably use EAN 32. If I know the sand is at 110' I'd use 36 or 37% - Generally for me, on dives to these depths, It's to a wreck, and there's not MUCH to see in the sand. I may spend a minute or two at the max, then work up.TheRedHead:You're limiting yourself to 45 minutes at 1.6. 1.6 is generally reserved for deco gas where you are not exercising.
Like the Spiegel Grove is at 132 FSW to the sand, so I dive 32% - but I'd probably spend the most amount of time on the dive between 90 and 110 FSW.