Petty officer third class Petty officer third class is the fourth enlisted rank in the U . S . Navy , U . S . Coast Guard , and the United States Naval Sea Cadet Corps , just above seaman and below petty officer second class , and is the lowest rank of non - commissioned officer , equivalent to a corporal in the U . S . Army and Marines . Petty officer third class shares the same pay grade as senior airman in the Air Force , which no longer has an NCO rank corresponding with E - 4 . History . Unlike the seaman and lower ranks , advancement to petty officer third class is not automatic given time in service , but is also contingent on performance evaluations by their superiors and rate examinations ( test of specialty knowledge ) , except for certain technical ratings which carry automatic advancement to PO3 , after successful completion of the rating ' s " A " school and fulfillment of time in rate requirements . The advancement cycle is currently every 6 months . Only a certain number of billet s ( job openings for this rank ) open up biannually and all seamen compete . The top scorers are chosen for advancement , but only in sufficient quantities to fill the billets available . Petty officers serve a dual role as both technical experts and as leaders . Unlike the sailors below them , there is no such thing as an " undesignated petty officer . " Every petty officer has both a rank and rating ( job , similar to an MOS or AFSC in other branches ) . The rank and rating combined are known collectively as a sailor ' s rate . A petty officer ' s full title is a combination of the two . Thus , a petty officer third class who has the rating of fire control technician is called a fire control technician third class . The term petty officer is , then , only used in abstract , the general sense , when referring to a group of petty officers of different ratings , or when the petty officer ' s rating is unknown . Each rating has an official abbreviation , such as FC for fire controlman . When combined with the petty officer level , this gives the shorthand for the petty officer ' s rank , such as FC3 for fire controlman third class . It is common practice to refer to the petty officer by this shorthand in all but the most formal correspondence ( such as printing and inscription on awards ) . Often , the petty officer is just referred to by the shorthand designation , without using the surname . Thus FC3 Burbie would just be called FC3 . To address a petty officer , one would say , " Petty Officer Smith " , " Smith " , or " Sailor " ( the latter two forms being acceptable for use by those equal or greater in rank than the Petty Officer ) . It is uncommon to address a petty officer as simply , " Petty Officer " the way one might address an NCO in the Marine Corps as " Sergeant " . Also acceptable , but archaic , would be to address a petty officer or chief petty officer of any grade as " Mister Smith " or " Ms . Smith " . The use of " Ms . " or " Mister " is commonly only in reference to junior commissioned officers or warrant officers . The rate insignia for a petty officer third class is a white perched eagle , and one specialty mark ( rating ) above a chevron . On dress uniforms , the symbol for the petty officer ' s rating will be placed between the two . On the dress white uniform , the eagle , rating , and chevron will be navy blue ( this has led to the eagle being referred to as the " crow " in common practice , and often the entire rating badge is simply referred to as the crow ) . On the dress blue uniform , the eagle and rating are white , and the chevron is red . The insignia that appears on working uniforms , such as the coveralls and naval working uniform , and metal rank devices like those on the collar of the naval service uniform have the rating symbol omitted . When a sailor is promoted the petty officer third class it is traditional for persons already holding that or a higher enlisted rank to " tack on the crow " . Originally , this custom involved a newly promoted sailor ' s fellow petty officers taking turns stitching the new rank on ( the rushed needlework referred to as tacking ) the sailor ' s uniform . More recently , however , the custom has taken on a different form , being done with a gesture ranging from a light tap to a hard punch over the new petty officers sleeve insignia . This , however , has been deemed as " hazing " in the recent past , and as such can subject individuals involved in this practice to disciplinary action . This disciplinary action often includes the individual being demoted . The " tacking on of the crow " has also been known to cause serious injury . It is not just patches that are tacked on but also metal insignia in the chest area that have sharp attachment pins , such as surface warfare or submarine service . A hard enough punch has been known to cause piercing of the skin by the attachment points . Commanding officers are also known to direct the ship corpsman to perform physical exams for possible abuse and to report all injuries to newly promoted personnel so that punishment for disobeying a direct order ( " no ' tacking on of awards ' " ) cannot be avoided . High year tenure . The U . S . Navy ' s high year tenure policy has made the good conduct variation for a petty officer third class all but obsolete . Among enlisted sailors , 12 consecutive years of good conduct ( categorized as no court - martial convictions or non - judicial punishment s ) entitles the sailor to wear a good conduct variation of their rank insignia : The normally red chevrons under the specialty mark and perched eagle are worn as gold and the eagle is worn as silver . However , the high year tenure initiative mandates that a petty officer third class may only have 8 years of service . If a PO3 fails to make petty officer second class within those 8 years , the petty officer is involuntarily separated for not meeting advancement requirements . This same restriction has recently been placed upon the rank of petty officer second class , allowing for only 14 years of service before advancement must be attained , and imposing a maximum enlistment of 20 years to a petty officer first class . All of these initiatives , however , may be waived in the event the sailor holds critical training qualifications , Navy Enlisted Classification ( NEC ) job codes , or clearances . Today , the few instances when a PO3 has gold chevrons are usually when a sailor has previous military service . The single gold chevron is " extremely " rare , but can still be found in Navy uniform shops . All U . S . Coast Guard petty officers wear red chevrons and red service stripes , until the rank of chief petty officer , where both chevrons and service stripes are gold . Royal Navy . In the British Royal Navy and navies of many other Commonwealth counties , the equivalent rank is " able seaman " , although this is considered junior to the nearest equivalent ranks of corporal or bombardier in the other military branches .