Republic of Korea Naval Special Warfare Flotilla The Republic of Korea Naval Special Warfare Flotilla ( ROKNSWF , SWF ; Hangul : ; Hanja : ) is a special warfare unit of Republic of Korea Navy . The flotilla is also known as ROKN UDT / SEALs , because the UDT / SEAL is the most publicly known branch of the flotilla . ROKNSWF are heavily influenced by the United States Navy SEALs , which initially provided funding and expertise in the unit ' s creation , and still maintain a strong relationship by regularly undertaking joint cross training ( JCET ) several times a year , utilizing American helicopter and submarine assets , and enrolling students each year in U . S . Naval Special Warfare programs such as BUD / S and EOD school . Applicants and selection . The SWF teams take applicants among conscripts , petty officer s , and officers . Most petty officers and all conscripts now apply before basic training while officers apply after commissioning ( NA , ROTC , or OCS ) , completion of Surface Warfare Officer School ( SWOS ) , and after they have been assigned to a ship . The BUD / S ( Basic Underwater Demolition / SEAL School ) selection process is almost identical to the US Navy program , consisting of extreme physical and mental challenges such as Hell Week . The completion rate has been known to dip under 10 % and usually hovers between 30 - 40 % , leading to manpower problems as the unit continues to expand and has an increasing number of foreign commitments . Since 2010 , most washouts have been retained as support personnel and equipment maintenance staff . Those who survive the first ten weeks are trained in open and closed circuit diving , demolition , land warfare and tactics before receiving the special warfare pin . Units . Naval Special Warfare Flotilla : History . The ROKNSWF ( also known in popular culture as the ROKN UDT / SEALs ) were involved in reconnaissance missions in North Korea until 1980 when a number of operators were broken away to form the UDU intelligence unit . In 1993 the SWF were tasked with standing up a maritime counter - terrorism unit which later became the Special Missions Bn . In the late 1990s the main focus was on defense of the coast from frequent attempts by the North to infiltrate agents into the South using midget submarine s . SWF were involved in the 1996 Gangneung submarine infiltration incident caused by North Korean agents , and in 1998 the unit was involved in the recovery and search of a North Korean Yono - class submarine that had been accidentally snared in fishing nets near Sokcho , Gangwon Province . Since 2009 the SWF have formed the core of the Cheonghae anti - piracy task group deployed to the coast of Somalia . In the early morning of January 22 , 2011 , as part of Operation Dawn of Gulf of Aden , 15 SWF operators boarded the 11 , 000 - ton chemical freighter " Samho Jewelry " which was taken by 13 pirates 6 days prior ; 21 sailors had been held hostages . ROKS " Choi - Young " , a 4600 - ton destroyer , dispatched its SWF team at 4 : 58AM along with a Lynx helicopter which then circled the ship and fired machine guns to distract the pirates . The boarding party of 15 SWF killed 8 pirates and captured 5 without taking any casualties after 3 hours of intense firefighting . All 21 hostages were secured , with one hostage suffering a non - fatal gunshot wound to the abdomen . Weapons . The weapons and equipment of the ROKNSWF are a mixture of indigenous and foreign manufacture . The Korean K1 carbine , K201 grenade launcher , K3 SAW , K5 pistol , and K7 suppressed submachine gun are all widely used in addition to the Heckler & Koch MP5 A5 and MP5SD6 submachine guns for VBSS and CT , the HK416 assault rifle , Beretta 92 FS , Sig Sauer P226 Navy , and versions of the Arctic Warfare .