who are equipped with ROV (remote operated vehicles) to upkeep submarine equipment like wellheads. Fast Supply Intervention Vessels (FSIV): High-speed ships, (approximately ) with a smaller deck capacity. They can nevertheless transport passengers. They essentially serve for urgent delivery or small shipment. Crew Boats: Those vessels are meant to shuttle back and forth oil platform workers between the sea installation and land. They can be high-speed craft (NGV). Smaller vessels are used for cross-sites transports. The helicopter is also widely used, especially when the weather is tough like in North Sea. Stand-by/Rescue vessels: Ships destined to security, they keep patrolling around the installation and must be ready to intervene in case of sea fall, evacuation or fire fighting. They are used mostly in northern seas. Line Handling Vessels (LH): Vessels used for handling spies (mooring lines). ROV Support Vessels (RSV): Support vessel specialized in ROV (Remote Operate Vehicle) operation. Tug Supply Vessels (TS): Vessels used as a tug and in the supply of platforms. Oil Spill Response Vessels (OSRV): Vessels dedicated to responding to offshore oil spills. Diving Support Vessels (DSV): Vessels used as a floating base for professional diving services. Vessel crews Crew on these ships can number up to 36 crew members, depending on the size, working area, and whether DP equipped or not. Crane vessels and drill ships often have 100 to 200 people on board including a dedicated project team. Daily operations Crews sign on to work and live aboard the ship an extended period of time, this is followed by similar period of time off. Depending on the ship's owner or operator the time aboard varies from 1 to 3 months with 1 month off. Work details on platform supply vessels, like many ships, are organized into shifts of up to 12 hours. Living aboard the ship, each crew member and worker will have at least a 12-hour shift, lasting some portion of a 24-hour day. Supply vessels are provided with a "bridge" area for navigating and operating the ship, machinery spaces, living quarters, and galley and mess room. Some have built-in work areas and common areas for entertainment. The large main deck area is sometimes utilized for portable housing. Living quarters consist of cabins, lockers, offices, and spaces for storing personal items. Living areas are provided with wash basins, showers, and toilets. The galley or cooking and eating areas aboard ship will be stocked