List of yard and district craft of the United States Navy

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Yard and district craft of the United States Navy (short, easy version)

This article explains the small ships and boats the Navy uses to support bases and harbors. Their hull numbers all start with the letter Y. Status codes show if a craft is active (A), inactive (I), or precommissioning (P). Inactive ships are in reserve or disposed; precommissioning ships are under construction or on order.

What these ships do and how they’re used
- Yard and district craft are like auxiliaries but are smaller and less capable than ocean-going ships. They usually stay in harbors or coastal areas, though some move to new assignments.
- Because they’re smaller and more flexible, the Navy often repurposes or converts these craft. Some vessels have changed roles up to six times. Conversions can be environmentally or economically motivated (for example, turning fuel-oil barges into water barges, or converting open barges to covered barges, and vice versa).
- The designation YAG has been used for at least two ships involved in classified weapons tests. Some ships have also carried other classifications such as IX or AG.

Common hull types and examples
- YF: self-propelled barges; YFN: non-self-propelled.
- YCK: wooden barges.
- YFB: yard barges. Two are stationed at Guantanamo Bay: Leeward (YFB-92) and Windward (YFB-93).
- YFD: floating dry docks, reclassified as AFDM in 1945.
- YFR: self-propelled barges; YFRN: non-self-propelled.
- YG/YGN: self-propelled/non-self-propelled barges; YM/YMN: dredges (self-propelled vs. not).
- Net-laying and related craft include Aloe-class, Ailanthus-class, and Cohoes-class ships, many of which started as yard net tenders (YN).
- YO, YON, YOG, and YOGN: various barge types (self-propelled vs. not).

Numbers and eras
- Hull numbers: 1–256 were built before World War II; 257–1153 were built during World War II; 1154 and up were built after the war.

World War II and beyond
- In World War II, many private fishing boats and U.S. Fish and Wildlife Service vessels were pressed into patrol service. Some were modified to deliver refrigerated food to remote island bases. Later, purpose-built yard patrol craft were used to train midshipmen at the Naval and Merchant Marine academies.

Notable notes
- Four floating workshops were transferred to the Soviet Union in 1945 under Project Hula (hull numbers unknown).
- YSD-11-class crane ships and many tugs were reclassified over time (often becoming YTB, YTL, or YTM).
- YW barges (Cape Flattery-class) are self-propelled (YWN are not).
- Barriers boats: 19-foot, 9.5-ton Barrier Boats (19BB) were built to deploy and maintain port security booms; 13 unnamed boats were delivered in 2003. Other barrier-boat designs include TR-01 and related TR-xx models (about 30 feet long).

For more details, see the Navy’s full list of yard and district craft and related MARAD designations.