Offshore support vessel

An offshore support vessel (OSV) is a workboat serving offshore oil, gas, and wind installations rather than carrying cargo between ports. The class covers platform supply vessels (PSV) that run fuel, water, mud, and deck cargo to rigs, anchor handling tug supply vessels (AHTS) that tow and set rig anchors, and crew and walk-to-work units. OSVs carry large clear afterdecks, below-deck bulk tanks for drilling fluids, and dynamic positioning to hold station alongside a platform. Day rates, not freight, set their earnings, and the SUPPLYTIME charter form governs most OSV time charters.