Hi John,
My writs is a little over 18.5cm. This watch is big but quite comfortable to wear. I once tried the Big Pilot Top Gun and TG Miramar that are 48mm in diameter and these were way to big.
This 5002 is about 46mm in diameter and that is alright.
The little problem I have at the moment is with the strap. It is a small size and the small leg of the band is quite short for my wrist. Setting the buckle on the last hole is alright being a little loose. If set at the before last, it is too tight. This is probably a good excuse to get a new strap !
Cheers
tibo