Keyed on the number, not the name
Ships are renamed constantly and names are reused. Thousands of names in the register belong to more than one hull, so a database keyed on a name is a database that will eventually attach a fixture to the wrong ship.
Everything here hangs off the IMO number, which does not change when a ship is sold or renamed. The number is check-digit validated on entry, so a transposed pair of digits is refused at the door rather than becoming a hull nobody can find again.
101,900 hulls carry one. 75,596 have a deadweight on file and 26,304 do not. The ones that do not are shown as unknown, everywhere, and never as zero. A blank figure and a zero figure are different facts, and a zero-deadweight ship sorts to the top of an ascending range search and poisons the answer.
Four owners, and the one you need is rarely the first
"Who owns this ship" has four answers and they are routinely four different companies: the registered owner on the certificate, the group that beneficially owns her, the technical manager who runs the engine room, and the commercial manager who fixes her.
A broker wants the last of those and it is almost never the one a public record leads with. The ownership chain is held as a chain, with each role named, rather than flattened into a single "owner" field that is wrong three times out of four.
45,386 hulls carry a commercial contact who can be e-mailed about a fixture. Where there is none, the hull says so. An empty contact is not an invitation to guess at an info@ address.
Shared reference, private corrections
One register, every desk
Desk and aboveThe fleet is shared reference data, so the same table serves every desk and no customer maintains their own copy of the world. It is roughly 350 MB and duplicating it per customer would be the wrong answer.
Your corrections ride on top
Desk and aboveA desk that knows better about a hull records it as an overlay: a correction and a private note, visible to that desk, sitting above the shared record rather than editing it. Your knowledge is yours and does not leak into anybody else's register.
Particulars and survey dates
Desk and aboveDeadweight, length overall, beam, draft, build year, flag, class society and the ownership chain, with port state control history where it exists.
Owners and managers directory
Chartering and aboveThe companies behind the hulls, searchable in their own right, with the fleets they run and the contacts the desk holds.
Outreach against the register
Fleet and aboveCampaign tracking across that contact database, so a desk chasing owners knows who it has written to and what came back.
What is not in it
No crane capacity, no hold or hatch dimensions, no tween decks. Those columns exist and are empty, which is worth saying plainly rather than leaving a project desk to discover in week two.
Summer draft is on roughly half the fleet. Live AIS positions are a separate thing on a separate screen and are not the register; a register says what a ship IS, and an AIS fix says where she was a few hours ago.