Old ships' boats may survive without a clear pedigree

Could small boats on British waterways unknowingly descend from Royal Navy ships' boats from the age of sail?

Yes, but proving it would be extremely difficult because thousands were built, repeatedly repaired, and followed a long-lived standard pattern from roughly 1760 to 1960.

Even small warships carried several boats, large ships carried many more, and dockyards produced additional craft for local work. The Royal Navy's durable boat patterns changed only incrementally, so physical resemblance can span two centuries without supplying a traceable identity.