Commercial vessels carry a variety of goods: dry bulk, tankers, containers etc.
The shipowner charters the vessel, contracting it with one or more companies to carry goods. They sail on a tight deadline; time is literally money. It is impossible to disrupt the trading pattern of a vessel for filming; you would never know when the vessel would be available.
Bunker tankers are a safer option. They are the smaller tankers that come into ports, load fuel and run it out to the larger ships at sea that are too big to come closer to the shore.
(The operation of refuelling is called bunkering.) Bunker tankers also come in various sizes. Cyprus is a place where vessels come for bunkering, so there are bunker tankers locally.
Ray Films is talking with one of the bunker companies, Island Oil. This company and their crew are used to having small training film crews from the European Maritime Safety Agency on board. The smaller the bunker, the more quickly it can turn and manuever, providing greater flexibility. They can sail closer to the shore so we don't waste time heading out to deeper seas.
