Also how will order be enforced? One cannot assume everyone will be nice and benevolent. What happens in a medical emergency, can you get to the nearest hospital in time (assuming the onboard facilities are insufficient)? The lead programmer just fell overboard during a storm, what happens?
This problem has been solved for cruise ships. I don't know the details of how, but surely the same issues and solutions apply pretty directly.
The law is either the nearest country (if you're 12 or 24 nautical miles away, depending on the circumstances), or the law of their flag state (if they are in the high seas). Generally, they avoid making arrests, and throw trouble makers out the next port. I think their registered home state generally turns a blind eye on what they do.
The "avoid making arrests, and throw trouble makers out" approach seems viable. Make sure companies on the boat post a bond for their employees that will cover throwing them out (sending them to their country of citizenship or the ships flag state for trial) if they won't/can't leave on their own.
> Also how will order be enforced?
This all too easily lends itself to some pirate jokes, perhaps revolving around vim users being forced to walk the plank.
That's not really how large ships work.
It's not that common for people to fall overboard accidentally.
Pay for some private military contractors, doctors, and a standby helicopter. Split the cost.
EDIT: If PMC are too militant, just any lenient security company would do. I don't really see how this is a problem. Think of it as a big festival with less alcohol and run for a longer time period.
IMO private military contractors are pretty much a non-answer to the problem of policing. I'd go as far as to say that PMCs are an inappropriate solution to any problem that doesn't involve lots of people getting shot.
Festivals have to deal with minor security, not criminal problems. Police are still around - whether patrolling the area, or in an on-site office, or on the end of a phone call - to deal with any major problems (all the way up to rape and murder).