The Wave-class tankers are a class of fast fleet tankers in service with the Royal Fleet Auxiliary. The class is tasked with providing fuel, food, fresh water, ammunition and other supplies to Royal Navy vessels around the world. There are two ships in the class, and . The ships were ordered to replace the aging s and . The two vessels have seen service in a number of locations, including anti-drug and hurricane relief operations in the Caribbean Sea, anti-piracy activities around the Horn of Africa, and deterrent patrols in the South Atlantic. As of early 2022, both ships were earmarked for "extended readiness" status (i.e. uncrewed reserve). History A contract was placed for the vessels in 1997 with Vickers Shipbuilding and Engineering Ltd (Marconi Marine VSEL). Construction of Wave Knight began in 1998 at VSEL's Barrow-in-Furness yard and the ship was launched in 2000. With the acquisition of Marconi Electronic Systems and its Marconi Marine subsidiary in 1999 British Aerospace became BAE Systems. BAE now owns VSEL in Barrow and the Yarrow and Govan shipyards on the Clyde. BAE transferred the construction of Wave Ruler to Govan in 2000 and the vessel was launched in 2001. Both vessels were commissioned in 2003. Design The ships have the capability to supply fuel and other liquid cargo to vessels using replenishment rigs on port and starboard beams and through a Hudson reel-type stern rig. When providing support for amphibious operations, the ships are also able to deliver fuel to dracones positioned alongside. The equipment load includes cranes (for stores handling and abeam replenishment), steering and rudder gear, thyristor-controlled winch/windlasses and double drum mooring winches. Up to of liquids and of general solids can be carried. In addition, reverse-osmosis equipment is fitted enabling the production of of drinkable water per day. The vessels were designed with double hulls to prevent or reduce environmental pollution from oil spills if damage is sustained to the outer hull. The ships can operate a Merlin HM1 helicopter, or other helicopters of similar size, from a hangar and flight deck at the stern. On deployments to Atlantic Patrol Task (N) they have typically embarked a Royal Navy Lynx or a United States Coast Guard helicopter. The vessels have a standard crew of 80 Royal Fleet Auxiliary personnel with provision for a further 22 Royal Navy personnel to conduct helicopter and weapons systems operations. They carry a full