Arios (Arvos) Tauchkalkulator world time watch

I was lucky to find a specimen in almost mint condition of this impressive vintage watch from 1977. It has a very busy dial and not less than 5 bezels, 2 external and 3 internal. It has tachymetre scale, world time/gmt and 60 minute scale. It can also be used for calculating distance and speed. Furthermore it has both day and date. In the instructions for the chromed version - see more later - the watch is called ”Tauchkalkulator” which can be translated to ”dive calculator”.

The watch has three crowns. The upper rotates the GMT and Tachymetre internal bezels. The middle is used for setting time, day, date and winding. The lower crown rotates the 60 minute internal bezel. See a video here on Youtube.

My Arios (Arvos) from 1977 with black case and metal bracelet. Very impressive and contemporary 44 mm in diameter.

Please note that Arios is often mistaken as ”Arvos” because the hands in the logo can make it little difficult to read the name.

Click here if you want to know more about the history of the watch brand Arios and the Muros factory that owned the brand.


The black Arios 44 mm
The watch was launched in 1977 at the European Watch, Clock and Jewellery Fair, now known as Baselworld. The presentation read: Ideal for seaside holidays is this moderately priced diving watch, waterresistant to a depth of 50 m (150 feet ). Matt black metal case and bracelet. It features two inner bezels: one for diving times, the other for reading the time in major centres around the world.

The original metal bracelet seems almost to be painted and it scratches very easily. The watch itself has a more solid black coating.

Original image of the black Arios 44 mm from Baselworld 1977. Source.

Dimensions
Width w/o crown: 44,3 mm
Width with crown: 46,8 mm
Length: 49 mm
Depth: 13 mm
Lugs: 25,9 mm

Two versions
The watch came in a version with manual winding (maybe Ronda 1217) and another with an automatic movement (Ronda-Matic). The manual has ”1600” on the back of the watch and the automatic version has ”1601”.
Actually being a new watch with a mechanical movement in 1977 was a little out of place. At this point quartz movements was all the rage but maybe the mechanical movement was a way to keep the price down.
Here is

My manual-wound Arios Tauchkalkulator 1600 with five bezels and a lot of functions. 44 mm and only 13 mm thick.

Arios Tauchkalkulator with the original metal bracelet. A +40 year old watch in almost unused condition.

Arios Tauchkalkulator from 1977. Great presence.

The version with manual-wind movement has ”1600” on the back. 

The version with automatic movement has ”1601” on the back. Source.

On the inside it says ”Arios Ltd” and ”MRP SA”. The watch case was produced by MRP that still exists today.

Arios Tauchkalkulator with an automatic movement has ”Automatic” in orange below the logo on the dial. Source

Chromed version
Arios also made a version with a chromed metal case which was very similar to the black version. It has only two crowns and the bezels are a little different and less colourfull.
The size of the chromed version are width w/o crown app. 44 mm, height 15 mm and length 46,3 mm.
It also came in a version with a 17 jewels Ronda 1217-21 manual wound movement (594 on the back of the watch) and another version with a 23 jewels Ronda-Matic automatic movement (1594 on the back).
My guess is that the chromed version came before the black version. The silver/chrome version seems to be more common than the black.
Here is a video with some close-up shots of the watch and movement.

Arios Tauchkalkulator with a silver/chromed case, 2 crowns, 5 bezels and a manual movement.

Same Arios but with an automatic movement. It says "Automatic" on the dial and "1594" on the back of the watch.

Instructions!
From this post we have the original instructions for the Arios Tauchkalkulator.

The original instructions for an Arios Tauchkalkulator with two crowns.

Below the Instructions translated from German with Google.

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Instructions for use for your ARIOS dive calculator

The calculator starting from the outer ring, has 5 ring scales, by which you can make different calculations.

1. Distance calculation:
An airplane flies at a constant speed of 200 km/h for 1 hour 30 minutes.
Question: What is the distance traveled?
A: Set external turning arrow to 200. Read result at 1 h 30 min = 309 km.

2. Speed calculation
The required time is 4 hours 30 minutes. The covered distance is 315 km. What is the average speed?
A: Set 4 hours 30 minutes (black ring) to 315 km (inner ring). Read result below the marking triangle = 70 km/h.

3. Driving speed calculation: (time calculation)
The speed is 160 km/h. The distance traveled 400 km. In which time will this distance be covered?
A: Set the triangle to 160 and read at 400. Result = 2 hours 30 min.

This watch has two crowns, right. The lower crown is for winding (for non-automatic watches) and for pointing the hands and setting the calendar. The calendar quickshift allows you to easily bring the calendar from 1-31 by turning the hands back to the desired date. After 24 hours the weekday changes to the next day.

The top crown is for the operation of the inner rotary ring, on which there are 2 parts. The inner indicates the respective local time. The outer has a minute scale.

Local time determination: (world time)
Assuming it is 11:00 and you want to know what time it is in Mexico. Set the position Roma (Rome = Berlin) on the turning ring exactly at 11.00 o'clock. Then look for Mexico on the turning ring and find it at pos. 3 h. The minus sign means that it is now 3 o'clock in the morning. The plus sign, on the other hand, indicates that it is 3 pm at the location in question.

Minute Scale:
For this one finds for any sport use. At the kickoff of a football game e.g. set the arrow on the rotary ring exactly on the extended axis of the minute hand. In this case you are in the picture during the game over the remaining time to play. The measurability of the ring is limited to 60 minutes.

Tachymeter (rally time)
The prerequisite is that the length of the route to be measured is known and that the second hand is at 60 when starting the measurement.

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Hopefully you have found some useful informations here. Thanks for reading.

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