Marine services provide repair, maintenance, logistics, testing, storage, and transportation services for boats, ships, oil tankers, and other watercraft. Marine repair services and marine maintenance services usually have facilities at boatyards, shipyards, and marinas. They perform on-water repairs and drydock maintenance, and can overhaul or upgrade boats and ships. Marine logistics services include freight haulers and freight forwarding agencies, as well as companies that provide logistical support to the offshore oil and gas industry. Marine storage services usually have steel boat racks and drystack storage buildings. Marine transportation services and other marine services are also commonly available.

Marine services can perform emergency repairs, periodic maintenance, or complete overhauls. Boats and ships require marine services while underway, at pier side, and during periods of reduced operating status (such as between charters or shipping seasons). Most oceangoing vessels require trips to special drydock facilities at regular intervals. Drydocks are basins that are used for shipbuilding or ship repair activities below a vessel’s waterline. They are flooded so that the ship can be floated in, and are then drained so that the ship comes to rest on a dry platform. Tasks done at drydock include the removal of biological growths from a ship’s hull, sandblasting and repainting the hull, and replacing the sacrificial anodes that are used to protect submerged equipment from corrosion.

Drydock services may also perform major repairs to a ship’s propulsion and steering systems, as well as to its major electrical systems. Marine propulsion systems consist of induction motors, generators, switchboards, and integrated automation systems. Marine steering systems include marine products and equipment for hydraulic steering and mechanical steering, as well as rudders and tiller arms. Marine services that specialize in drydock repairs and drydock maintenance may specialize in the repair and maintenance of complete propulsion systems, or individual components. Similarly, marine services that repair a ship’s electrical systems can maintain either complete systems or individual subsystems.

Some marine services provide offshore services, oil transportation, freight transportation, vessel manning, and brokering services. Offshore services are fabricators for the oil and gas industry. Using large structural steel components, they build various topsides and oil platforms. Oil transportation services and freight transportation services use oil tankers and other cargo vessels to transport crude oil and other petroleum products. Vessel manning services are marine services that provide contract or temporary crew members. Marine brokerage services may specialize in used commercial vessels or international shipping.