Global Ship Number System
GSN Home »Name search advice

The search is Case Insensitive.

If you know the exact name, input it and review the possible candidates. When specifying the search string to look for it is possible to use two "wild-card" characters in places where you are unsure about the spelling of a name.

  1. % (percent) matches any sequence of characters
  2. _ (underline) matches any single character

e.g.
The search string "MAR_ ANN_" will find "MARY ANNE", "MARI ANNA", etc.

If part of a name is known, e.g. BP tankers with names like "BRITISH CAPTAIN", you can enter "BRITISH C" to view the list of possibilities.

Once you have found the ship that you are looking for, click on either GSN or Official Number (in red) to reveal the other 'identities' of that ship. When presented with a large number of possible matches, it is possible to select which page you would like to jump to by clicking the page number below the results. Similarly, you can click the arrows to navigate through the results one page at a time.

GSN search advice

It is possible to search the system for a ship based on its GSN (Global Ship Number). This is a unique identifier for a ship that has been allocated by our system, and has no meaning outside the system. This type of search is likely to be used to check alternative identities of a particular vessel, hence click on the GSN of the ship displayed in red to see its other identities (or Official Number).

Official Number search advice

British and Commonwealth ships registered after 1855 were allocated an Official Number, ranging from 1 to 199999 in the years up to about 1957. As documents sometimes only contain Official Number but not name, it can be useful to 'decode' the Official Number. Blocks of Official Number's were allocated to each port, so are also a guide to the port of initial registration. Even if renamed, a ship kept the same Official Number while on the British register. Some countries, e.g. USA, also allocated Official Number's, some of which overlap with the British series, hence Official Numbers are not necessarily unique worldwide. Warships were not allocated Official Numbers.

Units for tonnage

The tonnage field may also include a marker code. The following abbreviations are used:

bm Builders Measurement (Pre 1850s)
csd Closed Shelter Deck (1907 Rule)
fl Full Load Displacement
grt Gross Registered Tons (DEFAULT)
gt Gross Tonnage (Post 1984 Universal Measurement)
lft Lifting Capacity (e.g. floating dock)
n Net Registered Tons (If only tonnage available)
nl Navy List Displacement (Pre 1921) (Warships)
osd Open Shelter Deck (1907 Rule) (Warships)
r Register Tons (1836 or later)
sd Standard Displacement (Post 1922)
tc69 Tonnage Convention of 1969
tmk Tonnage Mark (1970 Version)
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