The law is fairly clear, but the practice is not always so.
ALL the major accident investigations that has been involving MODUs has had the subject of “Line of Command” and lack of clarity as one of the reasons for the accident.
The title OIM on MODUs originate from that. (It was previously only used on fixed installations)
I have myself left a Drillship because I did not get backing of the Management when a dispute arose over who was in charge in emergencies.
If I’m going to be legally responsible for the safety of >100 persons, I’m going to have undisputable command.
As for DSVs this has been my pet subject when inspecting such vessels for some time. This is because I found that there was a tendency to run “two ships on one”. I.e. the Marine crew and the clint’s personnel operated as if they where on totally different units.
This manifested itself by talk of “Us and Them” when is come to things like Safety and implementation of SMS and HSE. Frequently I would find that there were three parties on board; Marine crew, Charterer personnel and Contractors. Each with their own Safety Management and HSE “culture” (or lack there off) and no coordination between them.
There may not be any joint Safety Meetings held, or Toolbox Talks to coordinate what they were doing, or any “Bridging Documents” between the various Operation and Emergency Procedures in use.
If you on top of that had a Company Repr. of the type described by the OP and a timid Master, the roots to a disaster is firmly in place.
The only place I know where there is no dispute on the authority of the Master/OIM is on Norwegian MODUs, where the two positions are the same. The OIM is ALWAYS a Master Mariner with additional qualifications as required to be in command of a MODU.
On some anchored MODUs the title OIM switches, depending on whether the unit is on the move or on location. I believe that in US waters some DP Semis and Drillships are operated like that??
As for FPSOs; the OIM is frequently from Production, unless it is self-propelled and disconnectable, thus requiring a Master. (Some companies prefer to have a Production man in charge on one hitch and a Master Mariner on the other)
Mr Heiwa; You obviously know very little about FPSOs, their operation and management.