What an interesting thread. Free of the constraint that we discuss boats, we can go on for pages! After I read them all I found I had these observations:

Bill: computer fractions: computers don't do meters and millimeters either, which is why metric dimensions are shown in millimeters. I often use a spreadshhet as a design aid and it's simple enough to make a spreadsheet display in inches, sixteenths and +/- for the 32nds, or whatever you want, including meters and millimeters if it comes to that. Most designers know enough to use a computer but not how to house-train it.

Doug: accuracy has nothing to do with the measuring system. The nice thing about an imperial scale is, it has 8ths (for ships), 16ths (for sailboats), 32ths (for canoes), 64ths and sometimes even 128ths (for models). So you can select the precision you need for the job. No such flexibility with metric, you got millimeters, take it or leave it, but it's OK for designing powerboats where you have to deal with nuts!

Tom: spreadsheets allow you to create your own number formats and link happily with graphic and text applications. Unfortunately CAD programs were generated by an entirely different bunch of people who never, as far as I know, adjusted their code to conform with the industry standard OLE interface, which is why you cannot just link you program to something like Excel and create the number format that suits your needs.

Bill: Canada spent millions changing all the street signs to kilometers and no doubt Canadians pay extra to have their US speedometers in clicks. Presumably so our Asian car manufacturers were not inconvenienced. A waste of money when our only neighbour deals in miles. Quebec went even further; they spent a similar sum changing all their signs, not just the mileage ones, from bilingual to French only.

Phil: the ten finger business in not just a therory. Metric is based on the decimal system. The reason that fingers and numeric symbols are both referred to as digits is .. well you work it out. No argumetnt with the international standardisation though, it's a great convenience. Pity they picked the wrong one, though ...

John: "No one is trying to rob anyone of their free choice ..." Oh, but they are. You hear it all the time from the pundits "they will never adopt metric fully while they are allowed to use the imperial system as well"
- thinking about it, I had better pop out and buy a few spare tape measures and scales as a hedge against the future.

Bill: a nautical mile is the length of an arcminute at the surface of the Earth, averaged because the Earth is not a perfect sphere. A fathom is 1/100 ths of a nm. In the metric system (which was originally proposed by an Englishman), the kilometre was originally defined as the length of an arc spanning a decimal arcminute at the surface of the Earth, but decimal angular measure (and the related decimal time) did not get adopted. So the unit is somewhat arbitrary; they would have done better, perhaps, to use the fathom to define the meter ...

Daan: I thought the use of centimeters and decimeters was officially discouraged a few decades back, which was the reason why cc's changed to ml' s, but I could be wrong ... while I'm on the subject, the deciliter makes no sense at all but it's extensively used in Europe.

: - just goes to show that no one system is a universal panacea. Use the system that works in your head and suits the job in hand, and "DONT GET HUNG UP ABOUT IT!!!" ...

: Les C

- my thought exactly!

AK (Terry Haines)

ps: if you don't have an imperial scale I recommend you use the metric system.