Grunff wrote:

The database will hold information that allows the
identification of the car/boat.

So for a car, it holds the make/model/colour/registration/year
of manufacture and where the car was at different times in it's
life.

I guess engine/chassis numbers would be rather more important.

Sadly, I know nothing about boats. So I'm asking for your help.
I need to build up a list of important parameters than can be
used to identify a boat. Not too many, maybe 6 at the most.

All of the above, plus name. The problem is that not all boats
are registered, and unless fairly recent, may well not have serial
numbers, so can be impossible to identify with certainty.

What is the purpose of your database? Being able to prove age
and history of location (in order, for example, to prove VAT
status), being able to recover stolen vessels, or just vague
general interest?