Short answer
A ship name is not a unique identifier. Treat the name as the beginning of identification, then confirm the vessel with date, operator, builder, route, or construction details.
Why names are reused
Shipping companies often revived names associated with earlier successful vessels, national figures, geographic places, or established fleet naming traditions. Ownership transfers could also produce duplicate names across different fleets and periods.
The strongest disambiguators
Launch or service yearA year in parentheses is often the fastest way to distinguish two ships with the same name.
OperatorThe same name can appear in different companies, or recur within one company decades apart.
Builder and yard numberShipyard identity and yard number are among the most stable technical identifiers available.
Route and career periodA ship serving Liverpool–New York in 1905 cannot be the same vessel as one launched in 1950 for Mediterranean service.
Do not infer identity from a famous name
Popular memory tends to collapse repeated names toward the best-known vessel. That is especially dangerous with names such as Britannic, France, Mauretania, Caronia, and Statendam.
Curator rule: when a name has been reused, include a year, operator, or other disambiguator until the context makes the identity unmistakable.