reverted to its original name in the early 1990s. Today, the unit is one of two operational elements within the Spanish Navy's Naval Special Warfare Force. The UOE collaborated and trained closely with similar NATO units, such as the United States Navy SEALs, the Italian Navy's COMSUBIN, the French Commando Hubert, and the Portuguese DAE, as well as with special intervention units of the Spanish police forces (UEI and GEO). The UOE and its parent Naval Special Warfare Force are one of only three units in the Spanish military formally tasked with Special Operations, along with the Army's MOE and the Air Force's EZAPAC. Selection and training After completing basic training and having served in a conventional unit, candidates aspiring to attain the "green beret" must undergo comprehensive medical and psychological reviews as well as physical trials, and then, if approved, pass a selection course (). The course is divided into Basic and Advanced phases and is staffed exclusively by UOE officers and NCOs, all of them fully qualified in special operations. The Basic phase lasts for about four weeks and is aimed at testing the physical and psychological endurance of candidates through a grueling combination of intense physical exercise, long-distance marches carrying up to of weight, and numerous trials at sea and in mountain environments. The Advanced phase of selection lasts for about two months and, though the physical rigor of the course steadily increases, candidates also receive more specific training in basic naval commando skills: Combat swimming Small-craft navigation Shipboarding Mountaineering and rappelling Demolitions Marksmanship Communications Hostage rescue Orienteering Escape and evasion in enemy territory Land/maritime survival techniques Battlefield medicine Candidates are free to drop out of the course at any moment, from the first day to the last. Though some drop-outs result from physical injury (or even death), most instances are voluntary. The attrition rate for the UOE selection process can occasionally be as high as 100% and averages from 70 to 80%—the highest failure rate of any course in the Spanish armed forces. It is not uncommon that by the end of the course the instructor-candidate ratio is 3:1. The unit's harsh entrance criteria have furnished its official motto, "" ("He who can enters, not he who wants"). Successful candidates are immediately sent to parachuting school on arrival at the UOE and proceed to more advanced and specialized training in Naval Special Warfare skills (diving, sniping,