Same as my diving. Have no idea of depth until actually on the water and know the real conditions at sites. It could be a 5m dive, it could be a 45m dive. The only gas that guarantees i can dive any of those safely is air.
I do often carry a side sling of 50 or 100% though to help with stops.
I do often carry a side sling of 50 or 100% though to help with stops.