Offshore supervision encompasses offshore/inshore oil and gas diving which is regulated by the national offshore regulatory authority responsible. In Australia, that is the National Offshore Petroleum Safety and Environmental Management Authority which acts under under federal/state mirror legislation.
Most other major oil fields have similar arrangments (the UK HSE and the Norwegian Petroleum Safety Authority in the North Sea and the US Coast Guard in the Gulf of Mexico for example). In Australian offshore operations, divers must be supervised by trained and certified ADAS Offshore Supervisors who must have complied with the ADAS training and assessment regime.
These supervisors must comply with the requirement to be experienced offshore commercial divers and have the requisite offshore supervisory and ALST panel hours etc. They will have ADAS licences that quite clearly state that they are either ADAS Air or Bell Offshore Supervisors.
These licences are recognised throughout the world by IMCA and also under the Canadian and Netherlands systems.