Y
- YA: Ash lighterf
- YAGR: Oceanic radar station
- YAGT: Target barge
- YC: Open Lighter
- YCD: Oil storage barge
- YCF: Car Float
- YCV: Aircraft Transportation Lighter
- YD: Floating Crane
- YDG: Degaussing tender
- YDT: Diving Tender
- YE: Ammunition storage barge
- 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 craft
- YHB: House boat
- YHLC: Heavy (salvage) lifting craft
- YHT: Heading scow
- YLA: Open lighter, landing
- YLLC: Salvage Lift Craft
- YM: Dredge
- YMN: Dredge (non-self propelled)
- YMT: Motor tug
- YN: Net tender
- YND: net tender, district
- 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
- 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, YTM, or YTM classifications)
- YTB: Large Harbor Tug
- YTL: Small Harbor Tug
- YTM: Medium Harbor Tug
- YTR: Rescue tug
- YTT: Torpedo Trials Craft
- YV: UAV recovery craft
- YW: Water Barge
- YWD: distilling craft
- YWN: Water Barge (non-self propelled)
Read more about this topic: List Of Hull Classifications