Regalo Slide Rule RG6005

Today's watch is a practical one for doing calculations, but isn't a calculator watch, and uses a technique that is not so common anymore.

The watch is by a band called Regalo, which got its name from the Italian for gift. The watches are Japanese, but are meant to represent the boldness and passion of Italy and be a fashion watch of European taste. It is manufactured by Maruman Products, who I've featured on the blog before.

The design is quite noticeable because of the huge size. The face is relatively normal, but the bezel is very thick to accommodate the unusual feature of this watch, a slide rule. The slide rule us a method for performing units conversion calculations. To make it work, you rotate the outer bezel to a required marker, and read off the result from another marker further around the dial. For example, if I line up the kilometres (km) mark with 60 on the outer dial, I can then check the Naut marker (for nautical miles) and see that points to a little under 33. This tells me that 60 km is around 33 Nautical Miles (actual answer is 32.4). The bezel also has speed markings in mph, and I haven't fully deciphered the rest of the numbers.

The time telling part is a quartz watch with a Miyota 6P09 movement. It uses a 3 hand dial design, with 4 small dials on the face. These smaller dials cover (clockwise from 12 o'clock) date, month, 24 hr time, and day. The time is set with the crown, and there is a push button on the side (above the crown) for date setting.

It was originally sold for around ¥9800, but doesn't seem to be available anymore.