I certainly wouldn't have an informed idea on how that could be handled, either. What I have to offer toward particulars amounts to spit balling 🤷‍♂️.

If I had to guess though, I'd bet you and @patchymoose@rammy.site are getting at it. A UN treaty could play a part in establishing a baseline to build up on. Perhaps the key could be to indirectly govern it rather than trying to directly govern happenings in international waters? Operations that depart from signing countries could guarantee that their vessels meet basic standards, even if those offshore operations are ultimately conducted in international waters.

I'd imagine that it may shift a noteworthy amount of operation departures to non-signing countries, but I'd also think that increasing the barrier of entry and making such standards highly visible would make a noteworthy difference regardless.