Unrestricted Line Officer Unrestricted Line Officers ( URL Officers ) are commissioned Officers of the Line in the United States Navy who are qualified to Command at Sea the Navy ' s warfighting combatant units such as warships , submarines , aviation squadrons and SEAL Teams . They are also qualified to command the higher echelons of those units such as destroyer and submarine squadrons , aviation wings and groups , and special warfare groups . At the Flag Officer level , they also command carrier strike groups , expeditionary strike groups , task forces , and Fleet and Force commands . URL officers are also eligible to command shore installations , facilities and activities directly supporting the Navy ' s warfare mission . URL officer specialities . URL officers include officers from the Surface Warfare , Submarine Warfare , Naval Aviation , and Special Warfare communities , i . e . , the Navy ' s " combat " communities . In this sense , all URL officers are considered warfare specialists and are designated as either Surface Warfare Officers , Submarine Warfare Officers , Naval Aviator s , Naval Flight Officer s , SEAL / Special Warfare Officers , or Special Operations Officers ( primarily Diver or Explosive Ordnance Disposal Officer / Diver ) . A URL community previously known as General Unrestricted Line is being phased out and no longer accepting new entrants . Officers in this category were not warfare qualified , nor on track to be warfare qualified , and were typically assigned to administrative and support tasks ashore . General URL officers have been replaced by the expansion of the Restricted Line Officer ( RL ) community into their former skillsets , with most incumbents laterally transferring into the Restricted Line . Unrestricted Line versus Restricted Line . Differentiated from URL officers are those naval officers whose functions are considered combat support in nature and are designated as either Restricted Line ( RL ) officers or Staff Corps officers . Examples of RL officers include Engineering Duty Officer , Aeronautical Engineering Duty Officer , Aircraft Maintenance Officer , Intelligence Officer , Information Warfare ( formerly Cryptology ) Officer , Meteorology / Oceanography Officer , Public Affairs Officer , Human Resources Officer , and Foreign Area Officer among others . Examples of Staff Corps officers include Supply Corps , Medical Corps , Dental Corps , Medical Service Corps , Nurse Corps , Civil Engineer Corps , Judge Advocate General ' s Corps and Chaplain Corps . Some RL officers begin their careers as URL and transition to RL , the most common examples being Surface Warfare Officers and Submarine Warfare Officers who become Engineering Duty Officers and Naval Aviators and Naval Flight Officers who become Aeronautical Engineering Duty Officers . Still other URL officers will transition into Staff Corps communities , most often Medical Corps or the Judge Advocate General ' s Corps following completion of Navy - funded medical school or law school . The remaining officers are directly commissioned as RL or Staff Corps . RL and Staff Corps officers are authorized to command ashore within their particular speciality , but are not eligible for combatant command at sea , which remains strictly within the purview of URL officers . Unrestricted Line versus Limited Duty Officers and Chief Warrant Officers . In contrast to the U . S . Navy ' s Limited Duty Officer s ( LDO ) and Chief Warrant Officer s ( CWO ) who are directly accessed from the senior enlisted grades ( E - 6 to E - 9 and W - 2 to W - 5 for LDO ; E - 7 to E - 9 for CWO ) , traditional Unrestricted Line Officers are required to possess at least a Bachelor ' s Degree and complete some type of formal pre - commissioning accession program . They are commissioned through programs such as the United States Naval Academy ( USNA ) , the Naval Reserve Officer Training Corps ( NROTC ) which also includes the Seaman to Admiral - 21 Program , and Officer Candidate School ( OCS ) . Some currently serving URL officers who are Naval Aviators or Naval Flight Officers were also commissioned via the since disestablished Aviation Officer Candidate School ( AOCS ) , either under traditional AOCS or its subset Aviation Reserve Officer Candidate ( AVROC ) or Naval Aviation Cadet ( NAVCAD ) programs . AOCS was merged into the current Officer Candidate School in the late 1990s . History . The United States Navy takes most of its traditions , customs and organizational structure from that of the Royal Navy of Great Britain . Based on the Royal Navy model , there were originally two kinds of officers on a naval ship of the line , the commanding officers , who were " gentlemen " and commanded the ship , and the warrant officer s , who were technical specialists who ran important tasks . In the nineteenth century , with the introduction of steam power , a third group of officers developed , engineers , who ran the steam plant . As the technology developed , the engineers were requesting more rights , including command . This system evolved in similar fashion in the Continental Navy during the American Revolutionary War and in the successor United States Navy into the nineteenth century . Eventually , this dispute led the Department of the Navy to abolish the differences between the groups , amalgamating them into Unrestricted Line Officers in 1899 . This fact can lead to confusion with non - American naval personnel , lacking the division between the two groups . The Russian Navy is an example of one with a difference between Deck and Engineer officers .