A platform supply vessel (PSV) is a ship specially designed to supply offshore oil and gas platforms.[1] These ships range from 50 to 100 metres (160 to 330 ft) in length and accomplish a variety of tasks. The primary function for most of these vessels is logistic support and transportation of goods, tools, equipment and personnel to and from offshore oil platforms and other offshore structures. In recent years, a new generation of platform supply vessels entered the market, usually equipped with Class 1 or Class 2 dynamic positioning system.

They belong to the broad category of offshore vessels (OSVs) that include platform supply vessels (PSVs), crane vessels (CV) and well stimulation vessels (WSVs), anchor handling tug supply vessels (AHTSVs) and offshore construction vessels (OCVs). Larger offshore vessels have extensive sophisticated equipment including remotely operated underwater vehicles (ROVs) and tend to accommodate a larger number of people (more than 100)[2]