These are cargo vessels that regularly transport goods, supplies or equipment in support of exploration or production of offshore mineral or energy resources. Offshore supply vessels are typically operated by shipowners: either companies set up specifically to own and operate such vessels or companies combine with other vessel operations like salvage, shipping, etc.

The OSVs can be divided into a number of types according to the operations they perform: seismic survey ships, platform supply vessels (PSV), anchor handling tugs, anchor handling tug and supply vessels (AHTS), offshore construction vessels (OCV), ROV support vessels, dive support vessels, stand-by vessels, inspection, maintenance and repair vessels (IMR) and variety of combinations of these.