High endurance cutter The designation of High endurance cutter ( WHEC ) was created in 1965 when the United States Coast Guard adopted its own designation system . High endurance cutters encompassed its largest cutters previously designated by the United States Navy as Coast Guard gunboats ( WPG ) , Coast Guard destroyer escorts ( WDE ) , and Coast Guard seaplane tenders ( WAVP ) . There are several classes of high endurance cutters that have operated with the United States Coast Guard ( USCG ) : Class History . " The Designations of the Cutter Fleet " The US Coast Guard ' s predecessor , the US Revenue Cutter Service designated its cutters and craft based on " classes . " From about 1890 through the formation of the US Coast Guard in 1915 , the largest cutters were referred to as vessels of the ' First Class . " The smaller coastal cutters and larger tugs were vessels of the " Second Class , " and the smaller tugs and cutters were designated as vessels of the " Third Class . " Finally , the small harbor craft were referred to as " Launches . " In 1915 , the newly formed US Coast Guard began referring to all of its larger cutters as " Cruising Cutters . " At that time , most of the smaller vessels fell under the classification of " Harbor Cutter " and the smallest craft were known as a " Launches . " This changed in 1920 when the Coast Guard divided the " Cruising Cutter " designation into " Cruising Cutters " for the largest seagoing cutters and " Inshore Patrol Cutters " for those that were primarily coastal vessels . In 1925 , the designation changed once again . Now the largest cutters were known as " Cruising Cutters , First Class , " while the coastal cutters were " Cruising Cutters , Second Class . " With Prohibition enforcement becoming a major mission , the US Coast Guard began adding numerous smaller patrol craft and these were grouped together under the classification of " Patrol Boats . " The service also acquired a large number of US Navy destroyers to augment the fleet and these were known as , simply , " Coast Guard Destroyers . " In February 1942 , the US Coast Guard adopted the US Navy ' s ship classification system whereby a vessel was designated with a two - letter abbreviation ( based on the type of ship ) and its hull number . Thus , the large , seagoing cruising cutters of the first class became gunboats , or " PG . " To differentiate them from their US Navy counterparts , all US Coast Guard cutters were given the prefix " W " at that same time . ( The W was an unused letter on the Navy ' s designation alphabet and was arbitrarily assigned to designate a " United States Coast Guard cutter " — it does not stand for any particular word . ) The US Coast Guard also began assigning an exclusive hull number to each cutter . After the end of the war and the US Coast Guard ' s transfer back to the control of the US Treasury Department , the US Coast Guard continued to use the US Navy ' s system . The large , seagoing cutters were classified primarily as " WPG , " " WDE " , and " WAVP " ( Coast Guard gunboats ; Coast Guard destroyer escorts ; and Coast Guard seaplane tenders ) . This changed in 1965 when the service adopted its own designation system and these large cutters were then referred to as Coast Guard High Endurance Cutters or " WHEC . " The coastal cutters once known as " Cruising cutters , Second Class " and then " WPC " ( Coast Guard patrol craft ) under the US Navy system were now Coast Guard Medium Endurance Cutters , or " WMEC . " Patrol boats continued to be referred to by their US Coast Guard / US Navy designation , i . e . " WPB . " Regardless of their changing designations , the largest cutters in the fleet have always been ocean - going vessels capable of handling a multitude of missions in any weather . This is not meant to be a complete history of high endurance cutters . Rather , this page is an history of the differing types of ships the US Coast Guard has designated " high endurance " and the changes these cutters underwent over the years between World War II and the Millennium . References . 1 . US Department of Homeland Security . United States Coast Guard Historian ' s Office . http : / / www . uscg . mil / history / webcutters / WHEC _ Photo _ Index . asp 2 . US Department of Homeland Security . United States Coast Guard Historian ' s Office . http : / / www . uscg . mil / history / default . asp