In water recompression is very easy but not always accurate. There are tables in commercial diving books like the dive medic manual that are comprehensive but they're not so great for repetative diving. Like the US Navy table has info to 90m but it's for single dives.

I would however strongly recommend a full face mask to prevent drowning from cns toxicity if using pure oxygen.

You need a good support team, a good buddy and proper gas to do it effectively.

but if you're offshore you don't have much choice.