It was during Baselworld 2018 that Robert-Jan and myself met with Jacob Hatzidimitriou. Jacob had contacted us and would like to show us his Ianos Avyssos diver’s watch that he intended to introduce. Something which is asked us more often and, because the majority of these intentions have to be addressed as ‘well-meant but not pertinent necessary’, which we did not have very high expectations of.

These expectations, however, changed immediately after Jacob handed us a prototype of his watch.

The Ianos Avyssos diver’s watch and its relation to Symian sponge divers finding the Antikythera mechanism

And that was just the watch. With a family heritage in sponge diving, to Jacob, it’s very important that the story behind his watch project will be told as well. This is the story by which he was inspired and to which he dedicates the watch. And I have to admit, it’s an interesting story indeed. A story about ancient Greek and brave sponge divers, before scuba diving was even invented.

Ianos Avyssos

The Ianos Avyssos on my wrist


Let’s start with the brand name Ianos. Ianos is taken from the God Janus, who was a Roman God of beginnings and ends, gates, doorways, passages, transitions, duality, and time. So let’s say, pretty much everything. Beginnings and time might be the most important for Ianos. By the way, January – the beginning of the year – was named after Janus as well.

I have to ask Jacob, being Greek (which you would have guessed from his family name with four I’s in it), why he chooses a Roman God to name his brand after and not a Greek one. Janus is associated with the Etruscan God Culsans who is a God of beginnings and passages as well. However, he has no Greek equivalent. Although in mythology Janus is believed to come from Thessaloniki in Greece, he then moved to Latium in Central-Italy, where he founded the Roman law- and agricultural systems and money.

Ianos Avyssos


So far the inspiration for the Ianos brand name. Now, where does the model name Avyssos come from? Avyssos derives from the Greek ἄβυσσος, meaning one who inhabits the abyss. In the Greek version of the Hebrew Bible, the Septuagint, the abyss represents both the original unfinished creation and the Great Deep of the primordial waters of creation. So to say, the primal chaos before creation. A more modern-day explanation of abyss, however, is immeasurable deep waters. This is more adequate for a diver’s watch and will have been Jacob’s inspiration for his first watch’ model name.

Design elements

Ianos Avyssos

Running indicator

On to the inspiration for the design elements of the Ianos Avyssos, and now getting to the Greek sponge divers. A detail that immediately attracts attention is the wheel-formed dial opening at 6 o’clock. I learned from Jacob that the form of this opening in the dial was taken from the main gear of the Antikythera mechanism. The Antikythera mechanism is the oldest computer found by Greek sponge divers, just off the Greek island of Antikythera approximately 70 years BC. This opening in the dial happens to be not just an aesthetical offering. It’s the indication for the wearer of the watch to see if it’s running or not. A quite important feature, which even is mentioned as an essential one in the ISO 6425 Dive Watch Standard.

Ianos Avyssos


Index markers

On second glance you’ll mention the shape of the index markers. They’re not circular, nor square or stick markers. The shape of the Avyssos index markers is taken from the stones which sponge divers from the Greek island of Symi use as a weight to get to greater deeps as quickly as possible. They’re known as kampanelopetra (petra meaning stone in Greek) and have been used for millennia.

Ianos Avyssos

Dial and hands

There will be three dial variations of the Ianos Avyssos. They all have beautiful radial faded dials and are produced in the well-known sandwich construction. The straight hands fit well to this dial, and the minute and hour hand have been adequately made in different colors.

Some words on the Antikythera mechanism

As mentioned above, the shape of the remarkable running indicator of the Ianos Avyssos was taken from the Antikythera mechanism. The Antikythera mechanism was retrieved from the Antikythera shipwreck off Point Glyphadia on the Greek island of Antikythera in 1901. The wreck had been found in April 1900 by a group of Greek sponge divers who retrieved numerous large artifacts. On 17 May 1902, archaeologist Valerios Stais found that one of the pieces of rock had a gear wheel embedded in it. He initially believed that it was an astronomical clock, but most considered the device to be too complex to have been constructed during the same period as the other pieces that had been discovered.

Antikythera mechanism

The Antikythera mechanism

Investigations into the object were dropped until British science historian and Yale University professor Derek J. de Solla Price became interested in it in 1951. It was only after x-ray and gamma-ray images that in 1974 Price was able to publish a 70-page report on the construction and functionality of the mechanism. It pointed out to be a device capable of indicating exactly how the sky would look for decades to come – the position of the moon and sun, lunar phases, and even eclipses – but also calculated the timing of several panhellenic athletic games, including the ancient Olympic games.

Hublot's take on the Anthikythera mechanism

After the importance of the Antikythera mechanism became known it has been the inspiration for many expeditions to recover more of its parts and secrets. As well, many models and recreations of the mechanism have been made. The most playful being this one made out of LEGO, and the most well known to us watch aficionados, has to be the one made by Hublot. More official information on the Antikythera mechanism can be found at the Antikythera Research Project website, or through Wikipedia. And an explaining video can be found here on YouTube.

The modern part of the Ianos Avyssos

Besides all the inspiration from ancient Gods and Greek sponge-diver history, I’m glad there’s an essential modern design part to the Ianos Avyssos as well. Don’t get me wrong; I can fully understand the importance of a good story backing up a watch. However, with the SIHH – where there’s a proud story behind every watch – still fresh in my memory, I rather like to buy a good watch than a good story. The Ianos Avyssos is precisely that, a good watch. A watch which by itself attracts at first sight – as explained in the first paragraph of this article.

Ianos Avyssos

What is it that makes the Ianos Avyssos attract so energetically? For me, it’s very much the shape of the casing. The case has been designed to complement the wrist’s curvature and has sloped edges. It makes the watch look light and almost organic. And that’s exactly how it feels when wearing it as well as if it belongs to your wrist. It seems it just should be there.

An ingeniously designed casing

Additionally, the case back has been re-thought in a modern context and has been designed with a deep longitudinal groove running through it. The purpose of this groove is housing a NATO-type strap; it will sit in the mentioned groove and thus not add to the wearing height of the watch on your wrist. Not only does the watch wear very comfortable like this, but it also enables a quick strap change as well. Finally, using this kind of strap construction makes for safety. When caused by abusive force, one of the strap push-pins would break; the watch will stay strapped to your wrist by the other.Ianos Avyssos

Under the strap, a circular glass-covered opening can be found. It will show you the hand-winding Sellita SW216-1 mechanical movement. It might not seem an obvious choice to use a hand-winding movement in a diving watch. But this simple and efficient caliber very much equals the way sponge divers use simple and efficient, tested and dependable tools like a rope and a rock. As well, a hand-winding movement brings the wearer closer to his watch. Every day he or she has an opportunity to touch and re-appreciate it.

Ianos Avyssos

The small round mineral glass revealing the hand-winding Sellita SW216-1 movement

To enhance the feeling of simplicity and functionality even further, the uni-directional rotating bezel and the screw-down crown both have been given bolt-like designs.


Price and specifications

I’ll finish this review listing some technical details, and information on price and availability. One shouldn’t be fooled here by numbers, though. In its form, the Ianos Avyssos is very different from any other watch you know, and thus very difficult to compare.

Ianos Avyssos

Halfway March 2019, a Kickstarter campaign was initiated to make the Ianos Avyssos available. The watch will be presented in two case variations, bare and PVD-coated stainless steel. There are four dial variations. The price for the Avyssos is CHF 1,250, excluding VAT.

Additional information can be found at, which is finished and online now.


Watch specifications

Gradient blue, sandwich style
Case Material
Stainless steel 316L
Case Dimensions
44 mm, 54 lug-to-lug
Slightly domed sapphire glass, faceted, with anti-reflective coating
Case Back
See-through case back with mineral glass, and NATO strap channel
Manual winding, Sellita SW216-1
Water Resistance
300 meter / 30 atm
NATO-style, water sustainable Italian leather, plus a rubber strap
Hours, minutes, running indicator
CHF 1,250 excluding VAT