Difference between revisions of "Hull Classification Symbol"

Latest revision as of 18:45, 18 September 2018

Breakdown of the various Ship Types, Hull Classification, and hip Types.

Anything marked with Underline is set to be links. Just surround your word using: <u> and </u> Still trying to figure out how to update the php.ini and over-ride the limit based on images being set at 7MB.

Warships

Warships are designed to participate in combat operations.

The origin of the 2 letter code derives from the need to distinguish various cruiser subtypes.

Cruiser	Armored	CA
	large	CB
	battle	CC
	Light	CL
	aviation or Voler	CV
Destroyer	ship	DD
Destroyer	Escort	DE

Warship Types

Aircraft Carrier

Aircraft carriers are ships designed primarily for the purpose of conducting combat operations by aircraft which engage in attacks against airborne, surface, sub-surface and shore targets. Contrary to popular belief, the "CV" hull classification symbol does not stand for "Carrier Vessel". The "CV" designation was originally derived from cruisers, since aircraft carriers were seen as an extension of the sea control and denial mission of cruisers. The "V" designation for heavier-than-air craft comes from the French verb voler (to fly). Since 1935, "CV" has been a two-letter, unitary hull classification symbol meaning "aircraft carrier". Aircraft carriers are designated in two sequences: the first sequence runs from CV-1 USS Langley to the very latest ships, and the second sequence, "CVE" for escort carriers, ran from CVE-1 Long Island to CVE-128 Okinawa before being discontinued.

CV: Fleet Aircraft Carrier (V) (1921–1975), Multi-purpose Aircraft Carrier (1975–present)
- CVA: Aircraft Carrier, Attack (category merged into CV, 30 June 1975)
- CVAN: Aircraft Carrier, Attack, Nuclear-powered (category merged into CVN, 30 June 1975)
- CVB: Aircraft Carrier, Large (Original USS Midway class, category merged into CVA, 1952)
- CVHA: Aircraft Carrier, Helicopter Assault (retired in favor of several LH-series amphibious assault ship hull codes)
- CVHE: Aircraft Carrier, Helicopter, Escort (retired)
- CVL: Light Aircraft Carrier (retired)
- CV(N): Night-Operating Fleet Aircraft Carrier (Used only by the former USS Enterprise (CV-6)
- CVN: Aircraft Carrier, Nuclear-powered
- CVS: Antisubmarine Aircraft Carrier (retired)
- CVT: Aircraft Carrier, Training (changed to AVT (Auxiliary)
- CVU: Aircraft Carrier, Utility (retired)
- CVG: Aircraft Carrier, Guided Missile (retired)
CVE: Escort Aircraft Carrier (retired) (1943–retirement of type)
- AV: Seaplane Tender (retired)
- AVC: Seaplane Tender, Catapult (Depot Catapult Ship ~ See Friesenland, Catapult Ship, and Air Force Catapult vessels / Seaplane tenders)
- AVG: Auxiliary Aircraft Ferry (Escort carrier) (1941–2)
- AVD: Seaplane Tender Destroyer (retired)
- AVP: Seaplane Tender, Small (retired)
- AVT (i) Auxiliary Aircraft Transport (retired)
- AVT (ii) Auxiliary Training Carrier (retired)
- ACV: Auxiliary Aircraft Carrier (Escort carrier) (1942)

Missing from List (British & German Catapult Ships);

Think these fit under the category of "Seaplane Tender" or Cargo Transports? IDEA: Which would be a nice addition too have as Information relay/jumpers//refueling stations across Star Systems.

AVC See above ~ German
CAM: Catapult Aircraft Merchantmen ~ converted freighters with rocket-propelled catapults to launch a plane from deck.
MAC: Merchant Aircraft Carriers ~ Larger ones were built specifically for this purpose ships, although most also transported cargo, but on which an aircraft deck was mounted on the aircraft and parked.

Surface Combatant

Surface combatants are ships which are designed primarily to engage enemy forces on the high seas. The primary surface combatants are battleships, cruisers and destroyers. Battleships are very heavily armed and armored; cruisers moderately so; destroyers and smaller warships, less so. Before 1920, ships were called "<type> no. X", with the type fully pronounced. The types were commonly abbreviated in ship lists to "B-X", "C-X", "D-X" et cetera—for example, before 1920, USS Minnesota (BB-22) would have been called "USS Minnesota, Battleship number 22" orally and "USS Minnesota, B-22" in writing. After 1920, the ship's name would have been both written and pronounced "USS Minnesota (BB-22)". In generally decreasing size, the types are:

BB: Battleship (B: pre-1920)
- BBG: Battleship, Guided Missile or Arsenal Ship (theoretical only, never assigned)
C: Cruiser (pre-1920 Protected Cruisers and Peace Cruisers)
- ACR: Armored Cruiser (pre-1920)
- CA: (first series) Cruiser, Armored (retired, comprised all surviving pre-1920 Armored and Protected Cruisers)
- CA: (second series) Heavy Cruiser, category later renamed Gun Cruiser (retired)
- CAG: Cruiser, Guided Missile (retired)
- CB: Large Cruiser (retired)
- CBC: Large Command Cruiser (retired, never used operationally)
- CC: Battlecruiser (retired, never used operationally)
- CC: (second usage) Command Ship (retired)
- CLC: Command Cruiser
- CG: Cruiser, Guided Missile
- CGN: Cruiser, Guided Missile, Nuclear-powered
- CL: Light Cruiser Cruiser Light (retired)
- CLAA: Cruiser, Light, Anti-aircraft (retired)
- CLG: Cruiser, Light, Guided Missile (retired)
- CLGN: Cruiser, Light, Guided Missile, Nuclear-powered (retired)
- CLK: Cruiser, Hunter-Killer (abolished 1951)
- CM: Cruiser-minelayer (retired)
- CS: Scout Cruiser (retired)
- CSGN: Strike Cruiser Cruiser, Strike, Guided Missile, Nuclear-powered

DD: Destroyer (D: pre-1920)
- DDG: Destroyer, Guided Missile
- DDE: Escort Destroyer (not to be confused with Destroyer Escort, DE: an Escort Destroyer; DDE, was a Destroyer, DD, converted for antisubmarine warfare) (category abolished 1962)
- DDK: Hunter-Killer Destroyer (category merged into DDE, 4 March 1950)
- DDR: Destroyer, Radar Picket (retired)
  - A radar picket is a radar-equipped station, ship, submarine, aircraft, or vehicle used to increase the radar detection range around a force to protect it from surprise attack, typically air attack. Radar picket vessels may also be equipped to direct friendly fighters to intercept the enemy.
- DM: Destroyer, Minelayer (retired)
- DMS: Destroyer, Minesweeper (retired)

FF: Frigate (retired)
- DE: Destroyer Escort (World War II, later became Ocean escort)
- DE: Ocean escort (abolished 30 June 1975)
- DEG: Guided Missile Ocean Escort (abolished 30 June 1975)
- DER: Radar Picket Destroyer Escort (abolished 30 June 1975)
  - There were two distinct breeds of DE, the World War II Destroyer Escorts (some of which were converted to DERs) and the postwar DE/DEG classes, which were known as Ocean Escorts despite carrying the same type symbol as the World War II Destroyer Escorts. All DEs, DEGs, and DERs were reclassified as FFs, FFGs, or FFRs, 30 June 1975.
- DL: Destroyer Leader (later Frigate) (retired)
- DLG: Frigate, Guided Missile (abolished 30 June 1975)
- DLGN: Frigate, Guided Missile, Nuclear-Propulsion (abolished 30 June 1975)
  - The DL category was established in 1951 with the abolition of the CLK category. CLK 1 became DL 1 and DD 927–930 became DL 2–5. By the mid-1950s the term Destroyer Leader had been dropped in favor of Frigate. Most DLGs and DLGNs were reclassified as CGs and CGNs, 30 June 1975. However, DLG 6–15 became DDG 37–46. The old DLs were already gone by that time.
- PF: Patrol Frigate (retired)
- FFG: Frigate, Guided Missile
- FFH: Frigate with assigned Helicopter
- FFL: Frigate, Light
- FFR: Frigate, Radar Picket (retired)
- FFT: Frigate (Reserve Training) (retired)
  - The FF, FFG, and FFR designations were established 30 June 1975 as new type symbols for ex-DEs, DEGs, and DERs. The first new-built ships to carry the FF/FFG designation were the Oliver Hazard Perry-class frigates. A new series of frigate-size warships for shallow-water combat at expense of battlegroup performance is under production:

K: Corvette (retired) ~
- DDC: Corvette (briefly proposed in the mid-1950s)

PG: Patrol Gunboat (retired)
PCH: Patrol Craft. Hydrofoil (retired)
PHM: Patrol, Hydrofoil, Missile (retired)
LCS: Littoral Combat Ship

M: Monitor (1880s–1920)
BM: Monitor (1920–retirement)

Ship Weight/Sizes

Add length, armament, crew, etc.

Battleship: ? Tons
Cruiser: ? Tons
Destroyer: ? Tons
Heavy Cruiser: 10,000 tons approx.
Frigate: (2,000+ tons) - {smaller Frigates (2-3,000 tons?)}
Corvette: 500–1,000 tons (454–900 metric tons)
Coastal Patrol Craft/Fast Attack Craft: (500 tons or less)

Submarine

Submarines are all self-propelled submersible types (usually started with SS) regardless of whether employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability. While some classes, including all diesel-electric submarines, are retired from USN service, non-U.S. navies continue to employ SS, SSA, SSAN, SSB, SSC, SSG, SSM, and SST types. With the advent of new Air Independent Propulsion/Power (AIP) systems, both SSI and SSP are used to distinguish the types within the USN, but SSP has been declared the preferred term. SSK, retired by the USN, continues to be used colloquially and interchangeably with SS for diesel-electric attack/patrol submarines within the USN, and more formally by the Royal Navy and British firms such as Jane's Information Group.

SC: Cruiser Submarine (retired)
SF: Fleet Submarine (retired)
SM: Submarine Minelayer (retired)
SS: Ship Submersible, Attack Submarine
SSA: Ship Submersible Auxiliary, Auxiliary/Cargo Submarine
SSAN: Ship Submersible Auxiliary Nuclear, Auxiliary/Cargo Submarine, Nuclear-powered
SSB: Ship Submersible Ballistic, Ballistic Missile Submarine
SSBN: Ship Submersible Ballistic Nuclear, Ballistic Missile Submarine, Nuclear-powered
SSC: Coastal Submarine, over 150 tons
SSG: Guided Missile Submarine
SSGN: Guided Missile Submarine, Nuclear-powered
SSI: Attack Submarine (Diesel Air-Independent Propulsion)
SSK: Hunter-Killer/ASW Submarine (retired)
SSM: Midget Submarine, under 150 tons
SSN: SSN (Attack Submarine, Nuclear-powered
SSNR: Special Attack Submarine (Nuclear-Powered)?
SSO: Submarine Oiler (retired)
SSP: Attack Submarine (Diesel Air-Independent Power) (alternate use), formerly Submarine Transport
SSQ: Auxiliary Submarine, Communications (retired)
SSQN: Auxiliary Submarine, Communications, Nuclear-powered (retired)
SSR: Radar Picket Submarine (retired)
SSRN: Radar Picket Submarine, Nuclear-powered (retired)
SST: Training Submarine
TSSBN: Trident Ship Submersible Ballistic Nuclear

AGSS: Auxiliary Submarine
AOSS: Submarine Oiler (retired)
ASSP: Transport Submarine (retired)
APSS: Transport Submarine (retired)
LPSS: Amphibious Transport Submarine (retired)
SSLP: Transport Submarine (retired)

SSP, ASSP, APSS, and LPSS were all the same type, redesignated over the years.

IXSS: Unclassified Miscellaneous Submarine
MTS: Moored Training Ship (Navy Nuclear Prototype School Training Platform; Reconditioned SSBN's)

Patrol Combatant

Patrol combatants are ships whose mission may extend beyond coastal duties and whose characteristics include adequate endurance and sea keeping, providing a capability for operations exceeding 48 hours on the high seas without support. This notably included Brown Water Navy/Riverine Forces during the Vietnam War. Few of these ships are in service today.

PBR: Patrol Boat, River, Brown Water Navy (Pibber or PBR-Vietnam)
PC: Coastal Patrol, originally Sub Chaser
PCF: Patrol Craft, Fast; Swift Boat, Brown Water Navy (Vietnam)
PE: Eagle Boat of World War I
PF: World War II Frigate, based on British River class.
- PFG: Original designation of USS Oliver Hazard Perry (FFG-7)
PG: Gunboat, later Patrol combatant
PGH: Patrol Combatant, Hydrofoil
PHM: Patrol, Hydrofoil Missile
PR: Patrol, River, such as the USS Panay (PR-5)
PT: Motor Torpedo Boat (World War II)
PTF: Patrol Torpedo Fast, Brown Water Navy (Vietnam)
PTG: Patrol Torpedo Gunboat
Monitor: Heavily gunned riverine boat, Brown Water Navy (Vietnam)
ASPB: Assault Support Patrol Boat, "Alpha Boat", Brown Water Navy; also used as riverine minesweeper (Vietnam)
PACV: Patrol, Air Cushion Craft, Brown Water Navy (Vietnam)
SP: Section Patrol, used indiscriminately for patrol vessels, mine warfare vessels, and some other types (World War I; retired 1920)

Amphibious Warfare

Amphibious warfare vessels include all ships having organic capability for amphibious warfare and which have characteristics enabling long duration operations on the high seas. There are two classifications of craft: amphibious warfare ships which are built to cross oceans, and landing craft, which are designed to take troops from ship to shore in an invasion.

Ships

AKA: Attack Cargo Ship (To LKA, 1969)
APA: Attack Transport (To LPA, 1969)
APD: High speed transport (Converted Destroyer or Destroyer Escort) (To LPR, 1969)
AGC: Amphibious Force Flagship (To LCC, 1969)
LCC: Amphibious Command Ship
LHA: General-Purpose Amphibious Assault Ship also known as Landing Helicopter Assault
LHD: Multi-Purpose Amphibious Assault Ship also known as Landing Helicopter Dock ~ IDEA: Cargo hold of Drop Ships, Attack & Support, Transport, Utility. The "Well" deck being an internal Air-dock, where as the main deck is for bigger craft and fast launch Attack/Assult & Support (Ammo/Refueling, etc.). See the WASP class
LKA: Amphibious Cargo Ship (out of commission)
LPA: Amphibious Transport
LPD: Amphibious transport dock
LPH: Landing Platform Helicopter
LPR: High speed transport
LSD: Landing Ship, Dock
LSH: Landing Ship, Heavy
LSIL: Landing Ship, Infantry (Large) (formerly LCIL)
LSL: Landing Ship, Logistics
LSM: Landing Ship, Medium
LSM(R): Landing Ship, Medium (Rocket)
LSSL: Landing Ship, Support (Large) (formerly LCSL)
LST: Landing Ship, Tank
LSV: Landing Ship, Vehicle

Landing Craft

LCA: Landing Craft, Assault
LCAC: Landing Craft Air Cushion
LCFF: (Flotilla Flagship)
LCH: Landing Craft, Heavy
LCI: Landing Craft, Infantry, World War II era classification further modified by
- (G) – Gunboat
- (L)- Large
- (M)- Mortar
- (R) – Rocket
LCL: Landing Craft, Logistics (UK)
LCM: Landing Craft, Mechanized
LCP: Landing Craft, Personnel
LCPA: Landing Craft, Personnel, Air-Cushioned
LCS(L): Landing Craft, Support (Large) changed to LSSL in 1949
LCT: Landing Craft, Tank (World War II era)
LCU: Landing Craft, Utility
LCVP: Landing Craft, Vehicle and Personnel
LSH: Landing Ship Heavy (Royal Australian Navy)

Combat Logistics

Ships which have the capability to provide underway replenishment to fleet units.

AC: Collier (retired)
AE: Ammunition Ship
AF: Stores Ship (retired)
AFS: Combat Stores Ship
AKE: Advanced Dry Cargo Ship
AKS: General Stores Ship
AO: Fleet Oiler
AOE: Fast Combat Support Ship
AOR: Replenishment Oiler
AW: Distilling Ship (retired)

Mine Warfare

Mine warfare ships are those ships whose primary function is mine warfare on the high seas.

AM: Minesweeper
AMb: Harbor Minesweeper
AMc: Coastal Minesweeper
AMCU: Underwater Mine Locater
MSO: Minesweeper, Ocean
MSC: Minesweeper, Coastal
MCM: Mine Countermeasures Ship
MCS: Mine Countermeasures Support Ship
MH: Minehunter
- (C) – Coastal
- (I) – Inshore
- (O) – Ocean
- (S) – Hunter and Sweeper, General
CM: Cruiser (i.e., Large) Minelayer
CMc: Coastal Minelayer
MLC: Coastal Minelayer
DM: High Speed Minelayer (Converted Destroyer)
DMS: High Speed Minesweeper (Converted Destroyer)

Coastal Defense

Coastal defense ships are those whose primary function is coastal patrol and interdiction. ~ IDEA: Use these for sector/system patrols?

FS: Corvette
PB: Patrol boat
PBR: Patrol Boat, River
PC: Patrol, Coastal
PCE: Patrol Craft, Escort
PCF: Patrol Craft, Fast, (Swift Boat)
PF: Frigate, in a role similar to World War II Commonwealth Corvette
PG: Patrol Gunboat
PGM: Motor Gunboat (To PG, 1967)
PR: Patrol, River
SP: Section Patrol

Mobile Logistics

Mobile logistics ships have the capability to provide direct material support to other deployed units operating far from home ports.

AD: Destroyer Tender
AGP: Patrol Craft Tender
AR: repair ship
AS: Submarine tender
AV: Seaplane Tender

Auxiliary Type

An auxiliary ship is designed to operate in any number of roles supporting combatant ships and other naval operations.

AN: Net Laying Ship
ARL: Auxiliary Repair Light—light craft or landing craft repair ship (World War II-era, out of commission)
ATF: Fleet Ocean Tug
AGHS: Patrol Combatant Support Ship—Ocean or Inshore

Airships

ZMC: Airship Metal Clad
ZNN-G: G-Class Blimp
ZNN-J: J-Class Blimp
ZNN-L: L-Class Blimp
ZNP-K: K-Class Blimp
ZNP-M: M-Class Blimp
ZNP-N: N-Class Blimp
ZPG-3W: surveillance patrol blimp
ZR: Rigid Airship
ZRS: Rigid Airship Scout

Support Ships

Support ships are not designed to participate in combat, and are generally not armed. For ships with civilian crews (owned by and/or operated for Military Sealift Command and the Maritime Administration), the prefix T- is placed at the front of the hull classification.

Support Type

Support ships are designed to operate in the open ocean in a variety of sea states to provide general support to either combatant forces or shore based establishments. They include smaller auxiliaries which, by the nature of their duties, leave inshore waters.

ACS: Auxiliary Crane Ship
AG: Miscellaneous Auxiliary
AGDE: Testing Ocean Escort
AGDS: Deep Submergence Support Ship
AGER: Environmental Research Ship
AGF: Miscellaneous Command Ship
AGFF: Testing Frigate
AGM: Missile Range Instrumentation Ship
AGOR: Oceanographic Research Ship
AGOS: Ocean Surveillance Ship
AGS: Surveying Ship
AGSS: Auxiliary Research Submarine
AGTR: Technical research ship
AH: Hospital ship
AK: Cargo Ship
AKR: Vehicle Cargo Ship
AKS: Store Issue Ship
AOG: Tanker (Gasoline Tanker)
AOT: Transport Oiler
AP: Transport
ARC: Cable Repair Ship (see also Cable layer)
APL: Barracks Craft
ARL: Small Repair Ship
ARS: Salvage Ship
AS: Submarine tender
ASR: Submarine Rescue Ship
AT: Ocean-Going Tug
ATA: Auxiliary Ocean Tug
ATF: Fleet Ocean Tug
ATLS Drone Launch Ship
ATS: Salvage and Rescue Ship
AVB: Aviation Logistics Support Ship
AVT: Auxiliary Aircraft Landing Training Ship
ID or Id. No.: Civilian ship taken into service for auxiliary duties, used indiscriminately for large ocean-going ships of all kinds and coastal and yard craft (World War I; retired 1920)

Service Type Craft

Service craft are navy-subordinated craft (including non-self-propelled) designed to provide general support to either combatant forces or shore-based establishments. The suffix "N" refers to non-self-propelled variants.

AB: Crane Ship
AFDB: Large Auxiliary Floating Dry Dock
AFDL: Small Auxiliary Floating Dry Dock
AFDM: Medium Auxiliary Floating Dry Dock
APB: Self-Propelled Barracks Ship
APL: Barracks Craft
ARD: Auxiliary Repair Dry Dock
ARDM: Medium Auxiliary Repair Dry Dock USS Oak Ridge (ARDM-1)
ATA: Auxiliary Ocean Tug
DSRV: Deep Submergence Rescue Vehicle
DSV: Deep Submergence Vehicle
JUB/JB : Jack Up Barge
NR: Submersible Research Vehicle
YC: Open Lighter
YCF: Car Float
YCV: Aircraft Transportation Lighter
YD: Floating Crane
YDT: Diving Tender
YF: Covered Lighter
YFB: Ferry Boat or Launch
YFD: Yard Floating Dry Dock
YFN: Covered Lighter (non-self propelled)
YFNB: Large Covered Lighter (non-self propelled)
YFND: Dry Dock Companion Craft (non-self propelled)
YFNX: Lighter (Special purpose) (non-self propelled)
YFP: Floating Power Barge
YFR: Refrigerated Cover Lighter
YFRN: Refrigerated Covered Lighter (non-self propelled)
YFRT: Range Tender
YFU: Harbor Utility Craft
YG: Garbage Lighter
YGN: Garbage Lighter (non-self propelled)
YH: Ambulance boat/small medical support vessel
YLC: Salvage Lift Craft
YM: Dredge
YMN: Dredge (non-self propelled)
YNG: Gate Craft
YNT: Net Tender
YO: Fuel Oil Barge
YOG: Gasoline Barge
YOGN: Gasoline Barge (non-self propelled)
YON: Fuel Oil Barge (non-self propelled)
YOS: Oil Storage Barge
YP: Patrol Craft, Training (Yard patrol boat)
YPD: Floating Pile Driver
YR: Floating Workshop
YRB: Repair and Berthing Barge
YRBM: Repair, Berthing and Messing Barge
YRDH: Floating Dry Dock Workshop (Hull)
YRDM: Floating Dry Dock Workshop (Machine)
YRR: Radiological Repair Barge
YRST: Salvage Craft Tender
YSD: Seaplane Wrecking Derrick
YSR: Sludge Removal Barge
YT: Harbor Tug (craft later assigned YTB, YTL, or YTM classifications)
YTB: Large Harbor Tug
YTL: Small Harbor Tug
YTM: Medium Harbor Tug
YTT: Torpedo Trials Craft
YW: Water Barge
YWN: Water Barge (non-self propelled)
ID or Id. No.: Civilian ship taken into service for auxiliary duties, used indiscriminately for large ocean-going ships of all kinds and coastal and yard craft (World War I; retired 1920)
IX: Unclassified Miscellaneous Unit
X: Submersible Craft
"none": To honor her unique historical status, USS Constitution, formerly IX 21, was reclassified to "none", effective 1 September 1975.

United States Coast Guard Craft

Prior to 1965, U.S. Coast Guard ships used the same designation as naval ships, but preceded by a "W" to indicate Coast Guard subordination.

CG: all Coast Guard Ships in the 1920s (retired)
WAGB: Coast Guard Polar-class icebreaker
WAVP: seagoing Coast Guard seaplane tenders (retired 1960s)
WDE: seagoing Coast Guard destroyer escorts (retired 1960s)
WHEC: Coast Guard High Endurance Cutters
WIX: Coast Guard Barque Eagle
WLB: Coast Guard buoy tenders
WLBB: Coast Guard seagoing buoy tenders/ice breaker
WLM: Coast Guard coastal buoy tenders
WLI: Coast Guard inland buoy tenders
WLIC: Coast Guard inland construction tenders
WLR: Coast Guard river buoy tenders
WMEC: Coast Guard Medium Endurance Cutters
WMSL: Coast Guard Maritime Security Cutter, Large (referred to as National Security Cutters)
WPC: Coast Guard patrol craft—later reclassed under WHEC
WPB: Coast Guard Patrol Boats
WPG: seagoing Coast Guard gunboats (retired 1960s)
WTGB: Coast Guard Tug Boat (140' icebreakers)

Temporary Designations

United States Navy Designations (Temporary) are a form of U.S. Navy ship designation, intended for temporary identification use. Such designations usually occur during periods of sudden mobilization, such as that which occurred prior to, and during, World War II or the Korean War, when it was determined that a sudden temporary need arose for a ship for which there was no official Navy designation.

During World War II, for example, a number of commercial vessels were requisitioned, or acquired, by the U.S. Navy to meet the sudden requirements of war. A yacht acquired by the U.S. Navy during the start of World War II might seem desirable to the Navy whose use for the vessel might not be fully developed or explored at the time of acquisition.

On the other hand, a U.S. Navy vessel, such as the yacht in the example above, already in commission or service, might be desired, or found useful, for another need or purpose for which there is no official designation.

IX: Unclassified Miscellaneous Auxiliary Ship, for example yacht Chanco acquired by the U.S. Navy on 1 October 1940. It was classified as a Minesweeper USS Kestrel (AMc-5), but instead, mainly used as a patrol craft along the New England coast. When another assignment came, and it could not be determined how to classify the vessel, it was redesignated IX-175 on 10 July 1944.
IXSS: Unclassified Miscellaneous Submarines, such as the USS Cod (IXSS-224), the USS Angler (IXSS-240) and the USS Croaker (IXSS-246).
YAG: Miscellaneous Auxiliary Service Craft, such as the USS George Eastman (YAG-39), USS Butternut (YAG-60) and USS Christiana (YAG-32) which, curiously, was earlier known as USS Christiana (IX-80).

Numerous other U.S. Navy vessels were launched with a temporary, or nominal, designation, such as YMS or PC, since it could not be determined, at time of construction, what they should be used for. Many of these were vessels in the 150 to 200 feet length class with powerful engines, whose function could be that of a minesweeper, patrol craft, submarine chaser, seaplane tender, tugboat, or other. Once their destiny, or capability, was found or determined, such vessels were reclassified with their actual designation.

National Oceanic and Atmospheric Administration Hull Codes

R: Research ships, including oceanographic and fisheries research ships
S: Survey ships, including hydrographic survey ships

Notes

Based from Hull Classification Symbol: US Navy
- A
A