Grunff writes:

Hi all,

I'm currently working on a database for a client which aims to allow
users to trace cars + boats they have owned in the past.


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.


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.


I know the term 'boat' covers a much wider range than 'car', but the
purpose of the database is to allow private individuals to trace their
old boats, so the range of boats will be limited to those which:


[a] Are likely to be owned by private individuals (no ocean liners or
oil tankers!)


and

[b] The owners are likely to want to trace. I don't suppose many
people whould be particularly interested in a small dingy they owned
20 years ago (maybe I'm wrong, I don't know).


Any help much appreciated.

Any sailing boat which has ever been raced (and quite a lot which
haven't) are likely to have a sail marking and a sail number. They are
likely to keep the same sail number for the whole of their lives (with
some rare exceptions - I believe in a few mass production dinghies the
sail number is the serial number of the _sail_, not an identifying
number of the _boat_). Note that there are very many classes, and each
class will issue numbers independently, so knowing the sail number is
not enough - you need to know the class as well (which is often but
not always indicated by a marking or logo on the sail). So you'd need
to record 'class' and 'sail number'. The sail number is alphanumeric,
not just digits - international classes will have the number prefixed
by some letters indicating the country of issue.

Most boats have a builders mark or plate somewhere; often this will
include a date or serial number. However, not all do.

Boats, unlike cars, are frequently repainted during their lifetimes,
so colour is not a good identifier.

Some boats are registered. However, the normal registry for small
private boats in the United Kingdom, the Small Ships Register, does
not as I understand it issue numbers for the lifetime of the vessel,
so the SSR number of a boat may change over its life.

The radio callsign and MMSI ('Marine Mobile Service Identifier')
number should not change provided the boat continues to be licensed to
carry a radio - but not all boats are.

Over all length, beam (width) and displacement (weight) are unlikely
to change in the lifetime of a boat, although, of course, some do get
modified.

Sorry this isn't more helpful!

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

;; If you're doing this for fun, do what seems fun. If you're
;; doing it for money, stop now.
;; Rainer Deyke