What is the significance of the AIS Shiptype number?

A vessel's type can be deducted using the information contained in the AIS-transmitted messages that she is emitting. The vessel's crew or the accountable officer are responsible for correctly entering this piece of information to the vessel's AIS transponder

AIS SHIPTYPE usually consists of two digits.

The first digit represents the general category of the subject vessel:

1 = Reserved
2 = Wing In Ground
3 = Special Category
4 = High-Speed Craft
5 = Special Category
6 = Passenger
7 = Cargo
8 = Tanker
9 = Other

In certain cases (e.g. Cargo Vessels, Tankers), the second digit provides additional information regarding the subject vessel's type of cargo, according to IMO.

1 = Category X
2 = Category Y
3 = Category Z
4 = Other Substances (OS)


The following table contains the relevant list:

10-19 Reserved Unspecified  
20-28 Wing In Grnd Wing in Grnd Wing In Ground Effect Vessel
29 SAR Aircraft Search and Rescue  
30 Fishing Fishing Fishing Vessel
Fishery Protection/Research
Fish Carrier
Fish Factory
Factory Trawler
Fish Storage Barge
Fishery Research Vessel
Fishery Patrol Vessel
Fishery Support Vessel
31 Tug Tug Towing Vessel
Tug/Supply Vessel
Tug/Fire Fighting Vessel
Tug/Pilot Ship
Anchor Handling Salvage Tug
Tug/Ice Breaker
Tractor Tug
Articulated Pusher Tug
32 Tug Tug  
33 Dredger Special Craft Suction Hopper Dredger
Drill Ship
Grab Hopper Dredger
Grab Dredger
Sand Suction Dredger
Hopper Dredger
Cutter Suction Dredger
Cutter Suction Hopper Dredger
Suction Dredger
Bucket Dredger
Trailing Suction Hopper Dredge
Trailing Suction Dredger
Inland Dredger
Drilling Jack Up
Bucket Ladder Dredger
Drill Barge
Bucket Hopper Dredger
Bucket Dredger Pontoon
Bucket Wheel Suction Dredger
Dredging Pontoon
Backhoe Dredger
Suction Dredger Pontoon
Water Jet Dredging Pontoon
Grab Dredger Pontoon
Kelp Dredger
34 Dive Vessel Special Craft Diving Support Vessel
35 Military Ops Special Craft Naval/Naval Auxiliary Vessel
Naval Auxiliary Tug
Logistics Naval Vessel
Mine Hunter
Combat Vessel
Command Vessel
Naval Salvage Vessel
Torpedo Recovery Vessel
Naval Research Vessel
Naval Patrol Vessel
Radar Vessel
36 Sailing Vessel Sailing Vessel Sailing Vessel
37 Pleasure Craft Pleasure Craft Yacht
Museum Ship
Exhibition Ship
Floating Hotel/Restaurant
Theatre Vessel
38 Reserved Unspecified  
39 Reserved Unspecified  
40-49 High-Speed Craft High-Speed Craft Hydrofoil
50 Pilot Vessel Special Craft  
51 SAR Search and Rescue Salvage/Rescue Vessel
Offshore Safety Vessel
Standby Safety Vessel
52 Tug Tug Icebreaker
Inland Tug
Pusher Tug
53 Port Tender Special Craft Tender
Crew Boat
Pilot Ship
Supply Tender
54 Anti-Pollution Special Craft Pollution Control Vessel
55 Law Enforce Special Craft Patrol Vessel
56 Local Vessel Special Craft  
57 Local Vessel Special Craft  
58 Medical Trans Special Craft Hospital Ship
59 Special Craft Special Craft Multi Purpose Offshore Vessel
Barge Carrier
Heavy Lift Vessel
Special Vessel
Maintenance Vessel
Pipe Layer
Waste Disposal Vessel
Supply Vessel
Training Ship
Floating Storage/Production
Radio Ship
Research/Survey Vessel
Repair Ship
Support Vessel
Fire Fighting Tractor Tug
Landing Craft
Floating Crane
Fire Fighting/Supply Vessel
Multi-Purpose Vessel
Tank-Cleaning Vessel
Mining Vessel
Fire Fighting Vessel
Paddle Ship
Anchor Handling Vessel
Nuclear Fuel Carrier
Sludge Carrier
Whale Factory
Utility Vessel
Work Vessel
Mission Ship
Buoy-Laying Vessel
Well Stimulation Vessel
Motor Hopper
Cable Layer
Anchor Handling/Fire Fighting
Crane Ship
Inland Supply Vessel
Offshore Supply Ship
Trenching Support Vessel
Offshore Construction Jack Up
Pile Driving Vessel
Replenishment Vessel
Construction Support Vessel
Pipelay Crane Vessel
Crane Barge
Work Pontoon
Production Testing Vessel
Floating Sheerleg
Mooring Vessel
Diving Support Platform
Support Jack Up
Trans Shipment Vessel
Floating Linkspan
Crane Jack Up
Pumping Platform
Air Cushion Vessel
Power Station Vessel
Supply Jack Up
Radar Platform
Jacket Launching Pontoon
Pipe Layer Platform
Pipe Burying Vessel
Air Cushion Patrol Vessel
Air Cushion Work Vessel
Pearl Shells Carrier
Steam Supply Pontoon
Jack Up Barge
Desalination Pontoon
Grain Elevating Pontoon
60-69 Passenger Passenger Passengers Ship
Inland Passengers Ship
Inland Ferry
Floating Hotel
Ro-Ro/Passenger Ship
Accommodation Ship
Accommodation Barge
Accommodation Jack Up
Accommodation Vessel
Passengers Landing Craft
Accommodation Platform
Air Cushion Passenger Ship
Air Cushion Ro-Ro/Passenger Sh
70 Cargo Cargo Passenger/Cargo Ship
Livestock Carrier
Bulk Carrier
Ore Carrier
General Cargo
Wood Chips Carrier
Container Ship
Ro-Ro Cargo
Heavy Load Carrier
Ro-Ro/Container Carrier
Inland Cargo
Cement Carrier
Vegetable/Animal Oil Tanker
Obo Carrier
Vehicles Carrier
Inland Ro-Ro Cargo Ship
Rail/Vehicles Carrier
Pallet Carrier
Cargo Barge
Hopper Barge
Deck Cargo Ship
Aggregates Carrier
Limestone Carrier
Ore/Oil Carrier
Self Discharging Bulk Carrier
Deck Cargo Pontoon
Bulk Carrier With Vehicle Deck
Pipe Carrier
Cement Barge
Stone Carrier
Bulk Storage Barge
Aggregates Barge
Timber Carrier
Trans Shipment Barge
Powder Carrier
Cabu Carrier
Vehicle Carrier
71 Cargo - Hazard X (Major) Cargo  
72 Cargo - Hazard Y Cargo  
73 Cargo - Hazard Z (Minor) Cargo  
74 Cargo - Hazard OS
75-79 Cargo Cargo  
80 Tanker Tanker Tanker
Asphalt/Bitumen Tanker
Chemical Tanker
Crude Oil Tanker
Inland Tanker
Fruit Juice Tanker
Bunkering Tanker
Wine Tanker
Oil Products Tanker
Oil/Chemical Tanker
Water Tanker
Tank Barge
Edible Oil Tanker
Lpg/Chemical Tanker
Shuttle Tanker
Co2 Tanker
81 Tanker - Hazard A (Major) Tanker  
82 Tanker - Hazard B Tanker  
83 Tanker - Hazard C (Minor) Tanker  
84 Tanker - Hazard D (Recognizable) Tanker Lng Tanker
Lpg Tanker
Gas Carrier
85-89 Tanker Tanker  
90-99 Other Other  


Note that, if you are using MarineTraffic API Services, it is possible to get SHIPTYPE responses such as those included in the next table (not AIS-derived):

100 Navigation Aid
101 Reference Point
103 OffShore Structure
104 Spare
105 Light, without Sectors
106 Light, with Sectors
107 Leading Light Front
108 Leading Light Rear
109 Beacon, Cardinal N
110 Beacon, Cardinal E
111 Beacon, Cardinal S
112 Beacon, Cardinal W
113 Beacon, Port Hand
114 Beacon, Starboard Hand
115 Beacon, Preferred Channel Port hand
116 Beacon, Preferred Channel Starboard hand
117 Beacon, Isolated danger
118 Beacon, Safe Water
119 Beacon, Special Mark
120 Cardinal Mark N
121 Cardinal Mark E
122 Cardinal Mark S
123 Cardinal Mark W
124 Port Hand Mark
125 Starboard Hand Mark
126 Preferred Channel Port Hand
127 Preferred Channel Starboard Hand
128 Isolated Danger
129 Safe Water
130 Manned VTS
131 Light Vessel