USN Ship Designations

By Guy Derdall and Tony DiGiulian
Updated 20 January 2016

Nomenclature History

Warships in the United States Navy were first designated and numbered in a system originating in 1895.  Under this system, ships were designated as "Battleship X", "Cruiser X", "Destroyer X", "Torpedo Boat X" and so forth where X was the series hull number as authorized by the US Congress.  These designations were usually abbreviated as "B-1", "C-1", "D-1", "TB-1," etc.  This system became cumbersome by 1920, as many new ship types had been developed during World War I that needed new categories assigned, especially in the Auxiliary ship area.  On 17 July 1920, Acting Secretary of the Navy Robert E. Coontz approved a standardized system of alpha-numeric symbols to identify ship types such that all ships were now designated with a two letter code and a hull number, with the first letter being the ship type and the second letter being the sub-type.  For example, the destroyer tender USS Melville, first commissioned as "Destroyer Tender No. 2" in 1915, was now re-designated as "AD-2" with the "A" standing for Auxiliary, the "D" for Destroyer (Tender) and the "2" meaning the second ship in that series.  Ship types that did not have a sub-classification simply repeated the first letter.  This meant that Battleships became "BB-X" and Destroyers became "DD-X" with X being the same number as previously assigned.  Ships that changed classifications were given new hull numbers within their new designation series.

The designation "USS" standing for "United States Ship" was adopted in 1907.  Prior to that time, no designation was used in official documents.  New-construction ships not yet in commission are currently prefixed with "PCU" which stands for "Pre-Commissioning Unit."

It should be noted that in the United States Navy, unlike European Navies, the first ship in a class to be authorized by the US Congress is the designated class leader (class name ship), regardless of the order in which the ships of that class are laid down, launched or commissioned.  For example, contrary to many European texts, for the last class of "Standard" battleships, the battleship USS Colorado BB-45 (commissioned 30 August 1923) is the class leader under USN designation standards, not USS Maryland BB-46 (commissioned 21 July 1921).  These battleships are thus properly designated as being "USS Colorado BB-45 Class" and not as "USS Maryland BB-46 Class."

Please note that the listings below include many designations that are no longer in use by the current-day US Navy and that others were proposed designations not actually used or were intended for ships that were never built.  Designations highlighted in Blue Font are for those ships actually in commission or currently under construction as of the present time (2015).

Aircraft Carriers
ACV Aircraft Carrier, Auxiliary
AVG Escort Carrier, Auxiliary
AVT Aircraft Carrier, Training Ship
CV Aircraft Carrier
CVA Aircraft Carrier, Attack
CVAN Aircraft Carrier, Attack, Nuclear Powered
CVB Aircraft Carrier, Large
CVE Aircraft Carrier, Escort
CVGH Aircraft Carrier, Guided Missile Helicopter
CVH Aircraft Carrier, Helicopter
CVHE Aircraft Carrier, Escort, Helicopter
CVL Aircraft Carrier, Light
CVN Aircraft Carrier, Nuclear Powered
CVS Prior to 1957:  Seaplane Carrier
CVS After 1957:  Anti-Submarine/Support Carrier
CVT Aircraft Carrier, Training Ship
CVV Aircraft Carrier, Vertical Take Off And Landing


The ex-collier USS Langley AC-3 was rebuilt and recommissioned as the first US aircraft carrier CV-1 on 20 March 1922.  The CVB designation was approved by the Secretary of the Navy on 10 June 1943 and the CVL designation was approved on 15 July 1943.  The CVS designation was established in 1953 with USS Bunker Hill (CVS-17) being the first so designated on 8 August 1953, although she was in reserve at the time and never did recommission.  The designation CVA replaced both CV and CVB on 1 October 1952.  CVL went out of use on 15 May 1959 when the last light carrier was decommissioned.  With the decommissioning of the last CVS in 1974, CV and CVN replaced CVA and CVAN on 30 June 1975 as carriers were now considered to be multi-mission capable rather than specialized.  The CV (non-nuclear) designation went out of service when the last conventionally powered carrier, USS Kitty Hawk CV-63, was decommissioned on 12 May 2009.

Escort Aircraft Carriers were originally designated AVG (Escort Carrier, Auxiliary) on 31 March 1941, with the USS Long Island AVG-1 being the first ship so commissioned on 2 June 1941.  This designation was changed on 20 August 1942 to ACV (Aircraft Carrier, Auxiliary), and then changed again on 15 July 1943 to CVE.  Escort Carriers built for the British Royal Navy were designated BAVG until they were transferred.  The CVE designation went out of use when the remaining escort carriers were reclassified AKV (Auxiliary, Aircraft Ferry) on 7 May 1959.

A common question is "what does the 'V' stand for in CV or CVA or CVS or CVE?"

[Thanks to C. Bossie who provided much of the following answer.]

The following is taken from "United States Naval Aviation 1910-1995, Appendix 16:  US Navy and Marine Corps Squadron Designations and Abbreviations":

On 17 July 1920, the Secretary of the Navy prescribed a standard nomenclature for types and classes of NAVAL VESSELs, including aircraft, in which lighter-than air craft were identified by the type "Z" and heavier-than air craft by the letter "V".  The reference also speculates that:  "The use of the "V" designation has been a question since the 1920s.  However, no conclusive evidence has been found to identify why the letter "V" was chosen.  It is generally believed the "V" was in reference to the French word volplane.  As a verb, the word means to glide or soar. As a noun, it described an aeronautical device sustained in the air by lifting devices (wings), as opposed to the bag of gas that the airships (denoted by "Z") used.  The same case may be regarding the use of "Z".  It is generally believed the "Z" was used in deference to Count Ferdinand von Zeppelin.  However, documentation has not been located to verify this assumption."
In European NATO Countries, "R" is used to designate an aircraft carrier.

B Battleship (prior to 1920)
BB Battleship (after 1920)
BBC Battleship, Command Ship
BBG Battleship, Missile
BBH Battleship, Helicopter
M Monitor (prior to 1920)
BM Monitor (after 1920)


The early pre-dreadnoughts Maine and Texas were commissioned as "Second Class Battleships" but apparently did not receive hull series numbers.  Maine was originally designated as Armored Cruiser #1 (ACR-1) but was reclassified during construction.

Many pre-dreadnoughts were colloquially known as "Coastal Defense Ships" as they were not designed nor intended to fight far from home.  Some of these were officially renamed as "Coast Battleship #X" (with "X" being their hull number) in March - April 1919 in order to free up their names for new construction.  Surviving pre-dreadnoughts were reclassified as "Battleships" and given the BB designation in the 17 July 1920 assignment, although many of these were then rapidly scrapped under the terms of the Washington Naval Limitation Treaty.

The "BBC" "BBG" and "BBH" designations were all for proposed conversions of Iowa class (BB-61) battleships.  The first two were developed during the 1950s while the last one was planned during the 1980s commissions.  None of these conversions ever took place.

Monitors were coastal defense ships of the 1890s, obsolete even as commissioned.

ACR Armored Cruiser (prior to 1921)
C Cruiser (prior to 1920)
CA Cruiser, First Line (1920 to 1921)
CA Armored Cruiser (1921 to 1931)
CA Heavy Cruiser - Cruiser armed with guns 8" (20.3 cm) or larger (after 1931)
CAG Guided Missile Heavy Cruiser - Heavy cruiser converted to carry missiles
CB Large Cruiser
CBC Large Command Ship
CC Battlecruiser (prior to 1961)
CC Command Cruiser or Command Ship (after 1961)
CF Flight-deck Cruiser
CG Guided Missile Cruiser
CGH Guided Missile Cruiser with an assigned Helicopter
CGN Guided Missile Cruiser, Nuclear Powered
CH Cruiser with an assigned Helicopter
CL Light Cruiser
CLAA Anti-Aircraft Light Cruiser
CLC Command Light Cruiser
CLD Light Cruiser, Dual-Purpose (AA and ASu)
CLG Guided Missile Light Cruiser - Light cruiser converted to carry missiles
CLGN Guided Missile Light Cruiser, Nuclear Powered
CLH Helicopter Light Cruiser - Cruiser with an assigned Helicopter
CLK Light Cruiser, ASW (submarine Killer)
CLV Aviation Cruiser
CS Scout Cruiser
CSG Strike Missile Cruiser
CSGN Strike Missile Cruiser, Nuclear Powered


The history of cruiser classification is somewhat complicated.  Initially, there were three major classifications:

Where "X" was the hull series number.

There were also older and non-classified cruisers which had not been assigned hull numbers.  As part of the 20 July 1920 redesignation mentioned above, there were the following four major changes:

Some cruisers changed categories and hull series numbers as a result of this reorganization.  For example, USS Minneapolis was previously designated as C-13 but was now designated as CA-17.

However, the Navy was not satisfied with this reclassification, and so there was a second reclassification on 8 August 1921.  On this date, Gunboats PG-28 to PG-34 and PG-36 were again classified as cruisers, this time as light cruisers CL-16 to CL-23, which left only USS Marblehead (PG-27, formerly C-11), still classified as a Gunboat.  Also on this date, USS Olympia (CA-15) was reclassified as a light cruiser (CL-15) and it was intended for the old cruiser USS Chicago (CA-14)  to be reclassified as a light cruiser (CL-14).  Thus, these ships changed classification, but retained their previous hull numbers.  Chicago was not actually redesignated and instead she was decommissioned in 1923 and became the uncommissioned barracks ship IX-5 at Pearl Harbor.

This classification system was used throughout the 1920s with the new 10,000 ton "Treaty" cruisers built during that time being commissioned into the CL hull number series, starting with USS Pensacola (CL-24).  Then, as a result of the provisions of the London Conference of 1930, cruisers were split into two categories, heavy and light.  The main differentiator was the size of the guns carried, with those cruisers having guns of 8" (20.3 cm) now being designated as "Heavy Cruisers" and those cruisers with smaller gun calibers being designated as "Light Cruisers."  On 1 July 1931, this new classification was officially adopted by the USN and the meaning of the "CA" designation was changed from "Armored Cruiser" to "Heavy Cruiser."  As a result of this reclassification, the "Treaty" cruisers USS Pensacola CL-24 through USS Portland CL-33 were redesignated as CA-24 through CA-33.  Thus, these ships retained their previous Light Cruiser hull series numbers, even though the last Armored Cruiser, USS Charleston, was CA-19.  From this time forward, all heavy and light cruisers built or planned between 1931 and 1949 used a single series of hull numbers, with the hull numbers interleaved between classes.  This interleaving created somewhat of a jumble in the sequence of hull numbers in the latter part of World War II, when the light cruisers of the Juneau (ii), Cleveland, Fargo and Worcester classes and the heavy cruisers of the Baltimore, Oregon City and Des Moines classes were all being built simultaneously.  The nuclear powered missile cruiser USS Long Beach, originally designated as CLGN-160, was the last ship to be numbered under this system, although she did not commission with this hull number, as noted below.

The Lexington class were the only battlecruisers ever laid down by the USN and were assigned hull series numbers CC-1 to CC-6.  When construction was suspended following the Washington Naval Limitation Treaty of 1922, the first two of these ships were then completed as aircraft carriers USS Lexington CV-2 and USS Saratoga CV-3.  The Alaska class of the 1940s were designated as Large Cruisers and assigned hull series numbers CB-1 to CB-6.  The USN did not considered these ships to be battlecruisers.

In the late 1940s and 1950s, four new cruiser classification groups were created:

Reflecting the obsolescence of their missile systems, on 1 May 1968 the Guided Missile Heavy Cruisers USS Boston (CAG-1) and USS Canberra (CAG-2) reverted back to their original Heavy Cruiser classifications CA-69 and CA-70, respectively, although they retained their Terrier missile launchers.

The designations "Cruiser," "Destroyer" and "Frigate" were a source of some confusion in the USN during the 1970s.  Existing US carrier escorts were designated as Frigates (DLG and DLGN), but foreign warships of the size of US Frigates were generally classified as destroyers or cruisers.  The USN was also applying the term "Patrol Frigate" or "PF" to the much smaller USS Oliver Hazard Perry class of convoy escorts then being designed.  This usage was more in line with the "Frigate" designation as used in foreign navies, where it was usually given only to smaller warships of about the same size as the Perrys.  On 30 June 1975, this issue was partially resolved when the following reclassifications were made:

This reclassification was incomplete, as the new Ticonderoga class Aegis missile ships were still planned to be designated as Guided Missile Destroyers (DDG-47 class), even though they were much larger vessels than the redesignated conventionally-powered cruisers (ex-DLG, now CG).  Finally, on 1 January 1980, the Ticonderoga class DDGs were redesignated as CGs and Ticonderoga herself was commissioned on 22 January 1983 as CG-47.  As the Ticonderoga class retained their originally planned hull numbers, this left a gap in the missile cruiser hull series sequence and hull numbers CG-43 to CG-46 were never assigned to any ship.  There was some thought that these unused numbers could be assigned to the new generations of nuclear-powered missile cruisers then being discussed (the revamped CGN-42 and CSGN classes), but none of these ships were ever built.  This redesignation of the early members of the Ticonderoga class also left a gap in the missile destroyer hull series sequence and hull numbers DDG-47 to DDG-50 were not reassigned to any ship.  USS Arleigh Burke, the first of a new class of missile destroyers, was commissioned on 4 July 1991 as DDG-51.

Destroyers, Escorts and Frigates
BDE Destroyer Escorts to be transferred to Britain during World War II
CG Destroyers loaned to the Coast Guard during 1924-1934
D Destroyer (prior to 1921)
DD Destroyer (after 1921)
DE Destroyer Escort, Escort or "Ocean Escort"
DEC Destroyer Escort, Control (Amphibious Control)
DEG Destroyer Escort, Guided Missile
DER Destroyer Escort, Radar Picket
DDE Destroyer converted to Fleet Escort
DDG Guided Missile Destroyer
DDH Destroyer with an assigned Helicopter
DDK Destroyer, ASW (Submarine Killer)
DDR Destroyer, Radar Picket
DL Destroyer Leader (1920 to 1955)
DL Frigate (after 1955)
DLG Frigate, Guided Missile
DLGN Frigate, Guided Missile, Nuclear Powered
EDD Destroyer, Experimental Test Ship (before 2005)
EDD Destroyer, Self-Defense Test Ship (after 2005)
EDDE Experimental Escort Destroyer
FF Frigate
FFG Guided Missile Frigate
FFH Frigate with an assigned Helicopter
FFT Reserve/Training Frigate
PE Patrol Escort
PF Frigate or Patrol Frigate
PFG Patrol Frigate, Guided Missile
PFR Radar Picket Frigate
TB Torpedo Boat

The United States built her first torpedo boat Cushing (TB-1) in 1890 and her last Wilkes (TB-35) in 1902.  Most of these were decommissioned or re-purposed prior to the start of World War I.  The surviving Torpedo Boats were renamed on 01 August 1918 as "Coast Torpedo Boat #X" where "X" was a new numeric series, starting with # 1.  This number was given to the former USS Foote (TB-3) which was now renamed as USS Coast Torpedo Boat # 1 (TB-3).  Like the old pre-dreadnought battleships mentioned above, this renaming of torpedo boats was done in order to free up their names for new destroyers.  All of these torpedo boats were decommissioned the following year and soon afterwards sold for scrap.  As these boats were all gone prior to the 17 July 1920 redesignation, the Torpedo Boat designation went out of service and was not replaced with a new one.  New small warships of about this size were now designated in the Patrol Vessel category.

The first USN destroyer was Bainbridge (D-1) which completed in 1902.  The designation for all existing destroyers was changed from "D-X" to "DD-X" as part of the 20 July 1921 redesignation mentioned above.  During prohibition, twenty-five destroyers were loaned to the US Coast Guard and these ships were redesignated as "CG-X" starting with USS Cassin (DD-43) which became CG-1 on 7 June 1924.  Most of these destroyers were scrapped following their return to the USN after the end of prohibition but a few were retained and given back their DD designation and hull numbers.

Following World War II, many Fletcher (DD-445), Allen M. Sumner (DD-692) and Gearing (DD-710) class destroyers were modified and given new, specialized missions as Fleet Escorts (DDE), Radar Pickets (DDR) and ASW submarine killers (DDK).  The ASW destroyers (DDK) were redesignated as Fleet Escort destroyers (DDE) on 4 March 1950.  All Fleet Escort destroyers (DDE) were reclassified as destroyers (DD) on 30 June 1962.  Most radar picket destroyers (DDR) were reclassified as destroyers (DD) during the 1960s.  One Fleet Escort destroyer USS Saufley (DDE-465) was reclassified as an Experimental Escort Destroyer (EDDE) on 1 January 1951 and then used as a test bed during the 1950s for sonar and ASW experiments.  She was reclassified as a general purpose destroyer (DD-465) on 1 July 1962.

USS Gyatt (DD-712) was modified to carry a twin Terrier launcher and she was designated as DDG-712 on 1 December 1956.  She was redesignated as DDG-1 on 23 May 1957.  Her missile emplacement was later removed and her designation reverted back to DD-712 on 1 October 1962.

The "DL" designation meaning "Destroyer Leader" was originally created as part of the 17 July 1920 designation system revision.  This designation was not assigned to any ship prior to 2 February 1951 when the ASW cruiser USS Norfolk CLK-1 was redesignated as DL-1 as described above.  In addition, the new fleet destroyers of the Mitscher class, which were originally designated in the DD series as DD-927 to DD-930, were redesignated on 2 February 1951 as DL-2 to DL-5.  This designation change was meant to indicate that these warships were significantly larger than those destroyers built during World War II yet still smaller than cruisers.  As none of these warships were really "leaders" in the sense of being equipped as destroyer flotilla leaders, the DL designation was reauthorized to mean "Frigate" on 1 January 1955.

The follow-on Farragut class frigates were originally to be an all-gun design and the first three ships of this class were designated as DL-6 to DL-8.  The next three ships starting with USS Coontz were to a similar design but were given a Terrier missile launcher and were designated accordingly as DLG-1 to DLG-3.  However, the Navy subsequently decided to equip the Farragut class with Terrier missile launchers and their designation was then changed to become DLG-6 to DLG-8 on 14 November 1956.  USS Coontz and her sisters were renumbered in sequence starting with DLG-9 on that same date.  As a result of these changes, all DL and DLG warships were in the same hull number series.

The Mitscher class frigates Mitscher DL-2 and John McCain DL-3 were converted to carry a Tartar missile launcher during the 1960s and they were then redesignated as missile destroyers DDG-35 and DDG-36, respectively, in 1968-69.  As noted above in the cruiser section, on 30 June 1975 most Frigates were redesignated as CG and CGN with the same hull number as previously, the exception being the Farragut DLG class which were redesignated as missile destroyers DDG-37 through DDG-46.

The designation "DE" was originally assigned to Destroyer Escorts of World War II.  The "DE" designation was changed to mean "Ocean Escorts" for those convoy escorts of the 1950s-1970s starting with the USS Dealey (DE-1006) class and ending with the USS Knox (DE-1052) class, but this was a seldom-used term.  The DANFS entry for USS Knox herself describes her as "the prototype in a new class of destroyer escorts" while the Naval Vessel Register (NVR) currently lists all DE-designated ships as simply "Escort" including those built during World War II.  As stated above, existing Guided Missile Escorts (DEG) were redesignated as Guided Missile Frigates (FFG) and those Escorts (DE) still in commission were redesignated as Frigates (FF) on 30 June 1975.

A number of Edsall (DE-129) class destroyer escorts were converted to Radar Pickets (DER) during the 1950s.  They carried that designation during the rest of their careers, although none of them appear to have been used in that role after about 1960.  Likewise, three DE (DE-698, DE-704 and DE-705) were converted to Amphibious Control Ships (DEC) in 1950-51 by adding extra communications gear, but they were all placed back into reserve by 1954 and the designation was abolished in 1957.  The control role was taken over by the APD flagships.

The "PF" designation was originally used for World War II frigates of the Asheville (PF-1) and Tacoma (PF-3) classes.  In the 1970s, it was proposed to designate what became the Oliver Hazard Perry (FFG-7) class as PF which would have then meant "Patrol Frigates."

During the late 1960s and early 1970s, a series of design studies were made for the "next generation" of ASW and guided missile carrier escorts.  These warship designs were given various interim designations, such as "DX" for the conventionally powered ASW destroyers, "DXG" for conventionally powered guided missile destroyers, "DXGN" for nuclear powered guided missile destroyers and "DG/Aegis" for an "austere" Aegis missile destroyer.  These proposals coalesced around what eventually became the conventionally powered Spruance (DD-963) ASW destroyers and Ticonderoga (CG-47) Aegis missile cruisers.  The nuclear powered version, which had grown considerably in size and was now known as a "Strike Cruiser" or CSGN and then later as the "CGN-42" class, was cancelled in the fall of 1978 although it was resurrected a few times until being cancelled once and for all in 1983.

A similar series of interim designations is currently in progress for new destroyer and cruiser designs, with the "DD-21" and "CG-21" designations having been replaced with the "DD(X)" and "CG(X)" designations.  The first destroyer in the DD(X) series will be christened as USS Zumwalt DDG-1000.  This means that these ships will be numbered in the DD series, rather than the DDG series, and it appears likely that the unused hull numbers DD-998 and DD-999 will not be assigned to any ship.

As expected, the schedule delays and ballooning costs of the Zumwalt class destroyers has resulted in additional orders for Arleigh Burke DDGs and it is now expected that advanced versions of this class will continue in production for at least the next decade.

The DD designation went out of service when "the last destroyer" USS Cushing DD-995 was decommissioned on 21 September 2005.  As noted above, the first US Torpedo Boat (TB-1) was also named Cushing.

In January 2015 the Navy announced that new ships in the Freedom (LCS-1) and Independence (LCS-2) classes would now be designated as Frigates (FF).  Existing ships may be redesignated, but this was not certain at this time (2015).

AGSS Auxilary/Experimental Submarine
APS Auxiliary Cargo Submarine
NSSN New Nuclear Powered Attack Submarine (temporary designation)
S Submarine (Attack/Fleet) - prior to 1920
SS Submarine (Attack/Fleet) - after 1920
SC Cruiser Submarine
SF Fleet Submarine
SM Submarine, Minelayer
SSA Auxilary/Experimental Submarine
SSAG Auxilary/Experimental Submarine
SSB Submarine, Ballistic Missile
SSBN Submarine, Ballistic Missile, Nuclear Powered
SSG Attack Submarine, Guided Missile
SSGN Attack Submarine, Guided Missile, Nuclear Powered
SSK Hunter-Killer Submarine
SSM Midget Submarine
SSN Attack Submarine, Nuclear Powered
SSP Transport Submarine
SSR Radar Picket Submarine
SSRN Radar Picket Submarine, Nuclear Powered
SST Submarine, Target/Training

Early submarines were given the designation "Submarine Torpedo Boats" (later shortened to just "Submarine") and most were given fish names.  On 17 November 1911 these names were discontinued and in their place was substituted an alphanumeric designation system representing their class and sequence.  For example, USS Bonita (S-15) was renamed as USS C-4 (S-15), with C-4 meaning that she was a member of the third class of USN submarines and the fourth submarine of that class.  Newer classes of submarines generally followed the letters of the alphabet, with "S" being the last letter used during the building spree generated by World War I.

Special note should be made here of the only US ship with a "half" hull number, the submarine USS Seal / G-1 which was assigned hull number S-19 ½, apparently because the Navy did not want her and thought that she would not be approved for service.  She was eventually redesignated as S-20 sometime prior to her decommissioning on 6 March 1920.  This was a reuse of the hull number previously assigned to USS F-1 which had been lost in a collision on 17 December 1917.

Following the reclassification of 1920, all of the older submarines changed their hull series number designation from S to SS, but new submarines built during the mid-1920s to 1931 period were separated into different hull number series, depending upon their assigned role.  Fleet Submarines (SF) were intended to scout ahead of the battle fleet, Cruiser Submarines (SC) were larger boats with heavy gun armament while the single Minelayer Submarine (SM) had special tubes for launching mines.  All of these newer submarines were given "V" alphanumeric names, although most of them were to differing designs.

This rather confusing practice of giving submarines both an alphanumeric name and an alphanumeric designation was continued until 1931.  In that and the following year, all of the submarines built since the mid-1920s were given fish names and redesignated into the SS hull number series.  The older submarines built during and immediately after World War I continued with their alphanumeric names (mainly the O, R and S classes).  New submarines built since 1931 have continued to be designated into the SS numeric series, with a few exceptions, as detailed below.

In a reprise of the alphanumeric naming of the 1911 to 1931 period, Training and Hunter-Killer submarines of the 1950s originally had only an alpha-numeric designation instead of a hull number.  Training submarine SST-1 was commissioned as "T-1" and SST-2 was "T-2."  On 15 May 1956 these training submarines were given fish names but they retained their SST designations and hull numbers throughout their service lives.  In a similar fashion, the "Hunter-Killer" ASW submarines SSK-1, SSK-2 and SSK-3 of that period were also given only alphanumeric names, "K-X" with the X being the same number as in their hull designations.  On 15 December 1955, these three boats were given standard fish names and on 15 August 1959 they were renumbered into the SS series.

The modern Seawolf class submarines were designated as SSN-21 to SSN-23, with this apparently meaning "21st century" submarine.  This designation seems to have been an aberration, as the follow-on Virginia class submarines continue the previous series, starting at SSN-774.

Some former Ohio (SSBN-726) class ballistic missile submarines were converted during the early 2000s into Tomahawk-carrying guided missile submarines (SSGN).

Amphibious Forces
AGC Amphibious Fleet Flagship
LC(FF) Landing Craft, Flotilla Flagship
LCAC Air Cushion Landing Craft
LCC Amphibious Command Ship
LCI Infantry Landing Craft
LCI(G) Infantry Landing Craft, Gun
LCI(L) Infantry Landing Craft, Large
LCI(R) Infantry Landing Craft, Rocket
LCM Mechanized Landing Craft
LCM/ML Minelaying Mechanized Landing Craft
LCP Personnel Landing Craft
LCP(L) Personnel Landing Craft, Large
LCP(N) Personnel Landing Craft, Nested
LCP(R) Personnel Landing Craft, Ramp
LCR Landing Craft, Rubber or Riverine
LCS Support Landing Craft (prior to 2004)
LCS(L) Support Landing Craft, Large (Rocket)
LCT Tank Landing Craft
LCU Utility Landing Craft
LCV Vehicle Landing Craft
LCVP Vehicle and Personnel Landing Craft
LCW Wing-in-Ground-Effect Landing Craft
LFR Inshore Fire Support Ship
LHA Amphibious Assault Ship, General Purpose
LHD Amphibious Assault Ship, Multi-purpose
LKA Amphibious Cargo Ship
LPD Amphibious Transport Dock Ship
LPH Amphibious Assault Helicopter Carrier
LPR Amphibious Transport, Small
LSD Dock Landing Ship
LSM Medium Landing Ship
LSM(R) Medium Landing Ship, Rocket
LSS Landing Support Ship
LSSL Small Landing Support Ship
LST Tank Landing Ship
LST(H) Tank Landing Ship, Evacuation (Hospital)
LST/ML Minelaying Tank Landing Ship
LSU Utility Landing Ship
LSV Vehicle Landing Ship

Most of the larger "Landing Craft" of World War II were later reclassified as "Landing Ships."

Littoral Warfare Ships
FSF Fast Sea Frame
LCS Littoral Combat Ship (after 2004)
PAC Air Cushion Patrol Craft
PB Patrol Boat
PBL Amphibious Assault Patrol Boat
PBM Riverine Monitor
PC Coastal Patrol Craft/Submarine Chaser (173 ft)
PCC Submarine Chaser (Control)
PCE Submarine Chaser (Escort)
PCEC Escort (Control)
PCE(R) Escort (Rescue)
PCI Fast Coastal Interceptor
PCS Submarine Chaser (136 ft)
PCSC Submarine Chaser (Control)
PE Eagle (steel patrol craft)
PG Patrol Gunboat or Corvette
PGM Missile Gunboat
PGH Helicopter Gunboat
PH Hydrofoil Gunboat
PHM Missile Hydrofoil
PHT Hydrofoil Torpedo Boat
PL High Endurance Cutters
PM Medium Endurance Cutters
PR Radar Picket Conversion
PSOC Special Operations Patrol Craft
PT Patrol Torpedo Boat
PTC Patrol Motor Boat Submarine Chaser
PW Wing-in-Ground-Effect Patrol Craft
PY Patrol, former Yacht
PYe Coastal Patrol, former Yacht
SC Submarine Chaser (110 ft)
SCC Submarine Chaser (Control)

The "PG" designation was given both to patrol gunboats built in the US during the first half of the twentieth century and to corvettes transferred from the Royal Navy under reverse lend-lease in 1942.

The "LCS" designation was originally assigned during World War II to "Landing Craft, Support."  In 2004, the USN reassigned this designation to the "Littoral Combat Ship" for the Freedom (LCS-1) and Independence (LCS-2) classes.  In January 2015 the Navy announced that new ships in these classes would now be designated as Frigates (FF).  Existing ships may be redesignated, but this is not certain at this time (2015).

Mine Warfare Ships
ACM Auxiliary Minelayer
AM Minesweeper
AMc Coastal Minesweeper
AMc(U) Coastal Minesweeper (underwater locator)
CM Minelayer
CMc Coastal Minelayer
DM Prior to 1955 - Light Minelayer (converted destroyer)
DM After 1955 - Destroyer Minelayer (converted destroyer)
DMS High Speed Minesweeper (converted destroyer)
MCAC Air Cushion Mine Countermeasures Craft
MCD Mine Countermeasures Drone
MCM Mine Countermeasures Ship
MCS Mine Countermeasures Support Ship
MCT Mine Countermeasures Conversion Trainer
MHC Coastal Minehunter
MHI Inshore Minehunter
ML Minelayer
MMD Fast Minelayer (ex-DM destoyers)
MSA Auxiliary Minesweeper
MSAC Air Cushion Minesweeper
MSC Coastal Minesweeper
MSCO Coastal Minesweeper, Old
MSD Drone Minesweeper
MSF Steel Hull Fleet Minesweeper
MSH Harbor Minesweeper
MSI Inshore Minesweeper
MSO Ocean Minesweeper
MSR River Minesweeper
MSS Special Device Minesweeper
YMS Motor Minesweepers

Those Benson and Gleaves class destroyers converted to minesweepers (DMS) during World War II were reclassified as destroyers (DD) during 1954/1955 and quickly thereafter decommissioned.

Converted Allen M. Sumner Light Minelayers (DM) were redesignated as Destroyer Minelayers (DM) on 7 February 1955 and redesignated as Fast Minelayers (MMD) on 1 January 1969.

Auxiliary Ships
AB Crane Ship (later changed to ACS)
AC Collier (coaling ship)
ACS Crane Ship
AD Destroyer Tender
ADC Dry Cargo Replenishment Ship
ADG Degaussing Vessel
AE Ammunition Ship
AF Refrigerated Stores Ship
AFDB Large Floating Drydock
AFDL Small Floating Drydock
AFDM Medium Floating Drydock
AFS Combat Stores Ship
AG Auxiliary, Generic/General (miscellaneous) use
AGB Icebreaker
AGD Seagoing Dredger
AGDE Experimental Destroyer Escort
AGDS Deep Submergence Support Ship
AGER Experimental Research Ship
AGF Fleet Flagship
AGFF Experimental Frigate
AGH Helicopter Support Ship
AGI Intelligence Gathering Ship
AGL Lighthouse Tender
AGM Missile Range Instrumentation Ship
AGMR Communications Major Relay Ship
AGOR Oceanographic Research Ship
AGOS Ocean Surveillance Ship
AGP Patrol Craft Tender
AGR Radar Picket Ship (converted cargo ship)
AGS Surveying Ship
AGSc Surveying Ship, Coastal
AH Hospital Ship
AHR Riverine Hospital Ship
AK Cargo Ship
AKA Attack Cargo Ship
AKE Dry Cargo Ship
AKL Light Cargo Ship
AKN Net Cargo Ship
AKR Roll-on/Roll-off Cargo Ship
AKS General Stores-issue Ship
AKV Aircraft Cargo Ship or Ferry
AN Net Laying (Net Tender) Ship
ANL Net Laying (Net Tender) Ship
AO Fleet Oiler
AOE Fast Combat Support Ship
AOG Gasoline Tanker
AOL Small Oiler
AOR Replenishment Oiler
AORL Small Replenishment Oiler
AOT Transport Oiler
AP Personnel Transport Ship
APA Attack Personnel Transport Ship
APB Barracks Ship
APc Coastal Transport
APD Troop Transport (High Speed)
APH Troop Transport, Hospital
APL Floating Barracks
APM Mechanized Artillery Transport
APR Rescue Transport
APV Aircraft Transport
AR Repair Ship
ARB Repair Ship, Battle Damage
ARC Cable Ship
ARD Repair Dock
ARDM Medium Repair Dock
ARL Repair Ship, Landing Craft
ARS Salvage Ship
ARS(D) Salvage Ship, Lifting Vessel
ARS(T) Salvage Ship, Tender
ARV Aircraft Repair Ship
ARVA Aircraft Airframe Repair Ship
ARVE Aircraft Engine Repair Ship
AS Submarine Tender
ASE Submarine Ammunition Ship
ASR Submarine Rescue Vessel
ATA Auxiliary Ocean Tug
ATGB Large Icebreaking Tug
ATF Fleet Tug
ATR Rescue Tug
ATS Salvage Tug
AV Seaplane Tender
AVB Aviation Logistics Support Ship
AVC Catapult Lighter
AVD Aviation Tender (Converted Destroyer)
AVP Small Seaplane Tender
AVS Aviation Supply Ship
AW Distilling Ship
AWK Water Tanker
AX Training Vessel (Current meaning)
Auxiliary Tender, Large (Former meaning)
AXS Sail Training Vessel
AY VIP Yacht (Current meaning)
Auxiliary Tender, Small (Former meaning)
AZ Aerostat Tender


Attack Cargo (AKA) and Attack Personnel Transport (APA) ships differ from Cargo (AK) and Personnel Transport (AP) ships by being specially equipped to partake in amphibious landings.  The AKA and APA designations were replaced by LKA and LPA as of 1 January 1969.

Plan Orange Conversions
XAV Seaplane Carrier, converted
XAVP Small Seaplane Carrier, converted
XCV Aircraft Carrier, converted

During the 1920s and 1930s Plan Orange included mobilization and conversion of various merchantmen and liners into auxiliary warships.  The number of suitable ships fluctuated throughout this period as older ships went to the breakers and newer ships were placed into service.  As of April 1939, ships available for conversions would have added five "fleet" carriers (none capable of more than 24 knots), two seaplane tenders and eight small seaplane tenders to the rolls.  These plans were all abandoned in November 1940, mainly because the conversions would have tied up too much shipyard capacity for little real gain.

Support Craft
AFSB Afloat Forward Staging Base Interim
DSRV Deep Submergence Rescue Vehicle
DSV Deep Submergence Vehicle
IX Unclassified Miscellaneous
IXSS Unclassified Miscellaneous Submarine
JHSV Joint High Speed Vessel
MLP Mobile Landing Platform
NR Nuclear Powered Research Submersible
SBX Mobile Radar
SDV Swimmer Delivery Vehicle
SLWT Side Loading Warping Tug
TWR Torpedo Retriever
WLB Seagoing Buoy Tender
WLM Coastal Buoy Tender
WLI Inland Buoy Tender
WLIC Inland Construction Tender
WLR River Buoy Tender
X-1 Midget Submarine (research vessel)
YAG Miscellaneous Service Craft
YC Lighter
YCF Car Float
YCV Aircraft Transportation Lighter
YD Floating Crane
YDT Diving Tender
YF Covered Lighter
YFB Ferry
YFN Covered Lighter
YFNB Large Covered Lighter
YFND Dry Dock Companion Craft
YFNX Special Purpose Lighter
YFP Power Barge
YFRT Range Tender
YFU Harbor Utility Craft
YGN Garbage Barge
YHLC Salvage Lift Craft, Heavy
YLC Salvage Lift Craft
YM Dredge
YMLC Salvage Lift Craft, Medium
YMN Dredge
YNG Gate Craft
YO Oil Barge
YOG Gasoline Barge
YOGN Gasoline Barge
YON Oil Barge
YOS Oil Storage Barge
YP Seamanship Training Craft
YPD Pile Driver
YPR Parasail Training Craft
YR Repair Barge
YRB Repair and Berthing Barge
YRBM Repair, Berthing, and Messing Barge
YRDH Hull Repair Barge
YRDM Machinery Repair Barge
YRM Missile Retriever
YRR Radiological Repair Barge
YRST Salvage Craft Tender
YRT Torpedo Retriever
YSR Sludge Removal Barge
YTB Large Tug
YTL Small Tug
YTM Medium Tug
YTT Torpedo Trials Craft
YW Water Barge
YWN Water Barge
YWO Waste Oil Barge

Old Ships

As part of the 17 July 1920 redesignation system, a series of "old ship" or "second line" designations was created in order to distinguish between front line ships and those that were past their prime.  As far as I have been able to determine, it would appear that these were not officially assigned to any ship.  This may have been a result of these old ships being scrapped as a result of the downsizing of the fleet following the end of World War I and the adoption of the Washington Naval Limitation Treaty.
OBM Monitor, Second Line
OCC Battle Cruiser, Second Line
OCA Cruiser, Second Line
OCL Light Cruiser, Second Line
OCM Minelayer, Second Line
OCV Aircraft Carrier, Second Line
ODD Destroyer, Second Line
OSS Submarine, Second Line
OSF Fleet Submarine, Second Line

USS Constitution

The two hundred year-old USS Constitution is unique in that she is the only ship in the USN that does not have a classification other than her name.  The Secretary of the Navy, J. William Middendorf, II, ordered her reclassification from "IX-21" to "None" effective as of 1 September 1975.  She is now listed on the Naval Vessel Register (NVR) of active in-commission ships only by her name.

Ship Naming in the US Navy

Note:  These links are to OFF-SITE webpages belonging to the U.S. Naval Historical Center.

Click here for U.S. Naval History Center FAQ #63

Ship nomenclature and Ship types

Page History

14 May 2007 - Benchmark
17 March 2009 - Added comments regarding redesignations of Mitscher class missile destroyers and extension of Arleigh Burke class DDG
17 September 2010 - Added "Old Ship" section and added information on Farragut class DLG designations
14 February 2014 - Added note about CV designation going out of use, minor changes for clarity in the cruiser and destroyer sections
01 June 2014 - Added DEC and description
30 March 2015 - Noted change from LCS to FF designation for new construction, added CVT to the Aircraft Carrier category and AFSB, JHSV and MLP to the Support Craft category, added note about Torpedo Boat renaming and corrected typographical error
14 May 2015 - Minor corrections for clarity, added SBX and YWO to Support Craft and added a mention of USS Seal / G1
20 January 2016 - Added note regarding transfer of destroyers to the US Coast Guard during prohibition


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