Prefix Meaning
AHT Anchor Handling Tug
AHTS Anchor Handling Tug Supply vessel
CRV Coastal Research Vessel
C/F Car Ferry
DB Derrick Barge
DLB Derrick Lay Barge
DCV Deepwater Construction Vessel
DSV Diving Support Vessel/ Deep Submergence Vehicle
DV Dead vessel[1]
ERRV Emergency Response Rescue Vessel[citation needed]
FPSO Floating Production, Storage and Offloading Vessel
FPV Free Piston Vessel
FPV Fishery Patrol Vessel
FV Fishing Vessel
GTS Gas Turbine Ship
HLV Heavy lift vessel
HMHS Her Majesty's Hospital Ship
HMY Her Majesty's Yacht
HSC High Speed Craft
HTV Heavy Transport Vessel
LB Liftboat
LNG/C Liquefied natural gas carrier
LPG/C Liquefied petroleum gas carrier
MF Motor Ferry
MS (M/S) Motor Ship (interchangeable[citation needed] with MV)
MSY Motor Sailing Yacht
MT Motor Tanker
MV (M/V) Motor Vessel (interchangeable[citation needed] with MS.
MY Motor Yacht
nb Narrowboat
NRV NATO Research Vessel
NS Nuclear Ship
OSV Offshore Support Vessel
PS Paddle Steamer
PSV Platform Supply Vessel
RV Research Vessel
RMS Royal Mail Ship or Royal Mail Steamer
SB Sailing Barge
SS (S/S) Steamship
SSCV Semi-Submersible Crane Vessel
SSV Sailing School Vessel
ST Steam Tug
STS Sail Training Ship
STV Sail Training Vessel or Steam Turbine Vessel
SV Sailing Vessel
SY Sailing Yacht or Steam Yacht
TEV Turbine Electric Vessel
TIV Turbine Installation Vessel
TS Turbine Steamer
TSS Turbine Steam Ship or Twin Screw Steamer
TV Training vessel
I didn't see HMS on the list (Despite HMHS being listed) which should be for His/Her Majesty's Ship. FWIW.
