How to Research a Yacht Name Change With an IMO Number

Two articles can use different names for what appears to be the same yacht. Before combining their histories, record the identifier each source actually gives. An IMO ship number can help connect the records, but a name match alone leaves room for confusion.

What an IMO ship number tells you

The International Maritime Organization’s identification scheme says a ship’s assigned number remains unchanged through its life despite changes of name, flag, ownership or type. Numbers of ships no longer operating are not reused. The IMO also describes a separate identification scheme for companies and registered owners. Do not confuse one of those numbers with the ship’s number.

The IMO lists pleasure yachts among the exemptions from the mandatory ship-number scheme. Do not assume every yacht has a number, or treat a missing number in an article as proof that the yacht does not exist.

Make one record for each source

Open the source itself and copy the name exactly as it appears, including spelling and punctuation. Keep separate notes for the two sources until you have compared them. A useful record has these fields:

• Name used: the vessel name printed in this source.
• Ship identifier: the number explicitly labelled as the ship’s IMO number, or “not provided.”
• Source: publisher, page title and address.
• Publication date: the date on the article or record, if shown.
• Event date: a separate date explicitly given for a name change or other event, if any.
• Access date: when you read the page.
• Uncertainty: missing fields, conflicting statements or an identifier whose label is unclear.

Do not promote an access date into an event date. Reading a page today does not establish that its name or ownership information describes today.

Compare the numbers before merging the histories

Matching ship numbers support a connection between the records, provided the sources and transcription are reliable. Check the complete number and its field label in both places. Repeated information copied from one article to another is not independent confirmation.

If the numbers differ, leave the records separate while you check for a copied digit, an unclear label or two different yachts with similar names. If one source supplies no ship number, record that gap. Do not fill it from the other source solely because the names or photographs look similar.

A matching number does not establish the rename date

Consider a fictional research example: Source A, published in March, uses an older name. Source B, published in June, uses a newer name and gives the same ship number. That supports investigating them as records of the same vessel. It does not prove that the name changed in June, or even between those publication dates; a page may describe an earlier event.

For a rename date, look for a source that explicitly describes the change and gives its date. Until then, a careful note is “Source B uses the newer name; exact change date unconfirmed.” Keep that statement distinct from any claim about an owner, buyer or reason for the change.

Leave a trail another reader can follow

Finish your notes with a short conclusion and its limits. For example: “These two sources give the same ship identifier under different names. The name-change date is not established by either page.” Link each clause to the source that supports it.

If a page later changes, preserve the access date and record the new observation separately. This approach gives you a usable research history without silently turning an uncertain match into a settled yacht biography.