UK law requires that those companies who are responsible for the safety of their offshore installation workers (duty holders) make arrangements to secure a “good prospect of recovery and rescue” and transfer to a “place of safety” for those who may find themselves in the sea in all but exceptional weather conditions. Those duty holders have contracted with specialized companies to provide the rescue services required by law. The ships and crews that undertake this work are specially equipped and trained to carry out marine rescue and recover survivors from lifeboats, liferafts, or directly from the sea. These specialized companies are represented by the Emergency Response & Rescue Vessel Association (ERRVA) and, between them, operate a fleet of Emergency Response & Rescue Vessels (ERRVs). An ERRV is alongside each offshore oil and gas installation or group of installations on the UK continental shelf continuously. Crew changes take place every 28 days, weather permitting. The ERRV also have tanker assist and firefighting capabilities. Rescue from the sea is normally carried out by fast rescue craft (FRC), which are about seven-meter long highly maneuverable rigid hull inflatable boats (RHIB) manned by a crew of three persons. Each ERRV carries at least two FRC. Daughter craft (DC) are larger than FRC and are capable of working at remote locations up to ten nautical miles from the ERRV. Once on board an ERRV, survivors are cared for in specially equipped treatment rooms by crew members who have been trained in medical and survival first aid. If a survivor requires specialist attention, he or she can be transferred ashore by helicopter. When not directly engaged in response and rescue work, ERRV provide ancillary services such as warning off shipping that poses risk of collision with an offshore installation, towage assistance, and pollution control. Since the program was established in 1986, ERRV have rescued over 378 persons, with approximately 50% not being related to the offshore oil and gas industry.