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Omega Seamaster 2501.3100 Wristwatch Review

By Rick Korchak


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Summary:  A beautiful and rare Omega Seamaster, this 25013100, purchased brand new in 1997, is unique and feels as solid as a rock!  It’s the perfect blend of dress and sporty and will fit under any sleeve cuff, unlike the monster dive watches of today.


omega-seamaster-120-25013100-close-up-face-aIt was 1997 and I had recently started a new executive position, my first senior management assignment. I needed a nice watch to match the job because my old cheap Casio digital, beat up from years of abuse, looked like an old pair of sneakers worn with a suit.

I was a dive watch fan from way back, having owned a new Zodiac Seawolf, bought for me by my parents as a high school graduation present (or bribe actually; it was the watch or I’d go surfing on graduation day rather than sit through a stuffy ceremony).

I was always an Omega fan, having first learned of the brand’s cachet from the film “King Rat”. But a new Omega was way beyond my means until that job came along.

I didn’t go out searching for an Omega, but happened to pass by an authorized dealer on Church Street in Orlando, Florida where I was living at the time. He had the usual array of Omega watches, including the “real” dive-oriented Seamasters, but I just didn’t think a pure dive watch would do it for me. I wanted something that wouldn’t look out of place with a suit and tie.

omega-seamaster-120-25013100-front-aThis Seamaster 120, model number 25013100 (or 2501.3100, depending upon whom you ask) was sitting in the display case. I really liked the very unique face with its Omega “waves” and the machined surface; you can see the concentric machining rings, an artifact of the cutting tool, circling the face, starting at the inside of the hour indices.

Move the watch back and forth in the light and there’s a star-like glint off those indices and a very cool rainbow-like pattern that sometimes appears on the machined surface. Needless to say, I was captivated.

The watch was about ten times more expensive than any other watch I owned up to that time, so I needed a couple of days to think about it. I can’t remember my entire chain of logic, but the bottom line was “I’ll take it!”. I’m glad I did.

omega-seamaster-120-25013100-hands-aI haven’t really worn this watch that much and completely stopped wearing it in 1999 when I came to my senses and left that overpaid but overworked executive position. Good riddance!

In 2009, I sent the watch to an authorized Omega repair center for a complete overhaul. It cost $395.00, which included the cost of shipping it back to me but not my shipping cost to send it there.

The watch was cleaned, adjusted, balanced and polished. I have the receipt, the old parts (only 3 gaskets needed replacing) and the timing receipt.

I wore the watch only once since then, so it’s time for it to go to a new home, to someone who will wear it more than I.

The Omega Seamaster 2501.3100: Size and Weight

omega-seamaster-120-faceThis Seamaster doesn’t look like any other Seamaster that I know of. In fact, I have never seen another like it, except for a photo or two on the internet. Search for “2501.3100” and you’ll basically come up empty, although a search for “25013100” does get a result or two, for some reason.

This is a mid-sized watch by today’s standards and certainly nowhere near as beefy as the modern-day Seamaster, much less the Planet Ocean in 42 mm or — yikes! — 45 mm diameter. The case makes it slightly difficult to measure, but it comes out right at 36 mm, according to my Vernier caliper.

And it’s thin, measuring only 10.3 mm. This means it fits under just about any shirt sleeve and the combination brushed and polished stainless steel case and bracelet look fantastic with that executive suit.

omega-seamaster-120-wristI still have the original box, all of the paperwork and even the original credit card receipt that came with the watch. Nowhere in the owner’s manual or on the watch is there an indication of the water resistance of this Seamaster, which is rather strange, considering that it is a Seamaster, one of the most famous dive watches ever made. But I have heard people reference it as the “Seamaster 120” and the “120” is a reference to the depth in meters that it is supposedly tested to.

In any case, this one has never been underwater at any time, either in the sink or the sea!

With two links out of the bracelet, the 2501.3100 fits my 7.25″ wrist. The links are still in their plastic bag, packed in the original box, of course! The watch weighs just 122 grams and this, combined with the thin case, makes it feel like it has disappeared on my wrist.

Omega Seamaster 2501.3100 Lume

One thing that this 1997 Seamaster does not have in common with the Seamasters of today is lume. You can see in the photos that this watch has only very tiny dabs of lume at the tip of the hour and minute hand and equally small dots of lume at the ends of each hour indice. It reminds one very much of a modern Vostok Komandirskie, which has a similar amount of lume; i.e., basically none.

Movement, Setting and Accuracy

omega-seamaster-120-25013100-box-cI’m not really sure which movement resides in the 2105.3100. The owner’s manual has very little information about the watch, other than how to set it and wind it. The back cover of the manual is inscribed “Cal. 1109/1111/1120”, which I assume means that the manual is valid for those three movements.

So I’ll have to assume that, like most of the other mechanical Seamasters of the period, this watch has the famed 1120 movement. I haven’t opened the case myself and I’m not about to.

If it is the 1120, then I believe it is based on the highly regarded ETA 2892-A2 movement. It is an automatic, and the 1120 has 23 jewels and a 44-hour power reserve. As you can see in the video, the second hand has a fine sweep across the face, probably due to the 28,800 beats per minute (BPM) action.

omega-seamaster-120-25013100-face-cThe watch has a “Chronometer Certificate”, which is nothing more than a booklet that says the watch meets COSC standards, which, I believe, are -6 to +4 seconds per day

Sweep second hand (moves in 1/8 second increments). Movement has received a Chronometer certificate from COSC, certifying that the mechanism is capable of accuracy within an average of -4 to +6 seconds per day. It hacks and has the quick-set date. Also, supposedly the 1120 has the date window closer to the outer edge of the face, which is apparent on the watch shown in my photos.

I usually wind the watch, then stop the minute and seconds hand at 12 in anticipation of the official NIST time as displayed on my trusty Casio Waveceptor. When the seconds hand on the Waveceptor hits 12, I push in the crown on the Seamaster and it’s ready to go.

Readability and Face

omega-seamaster-120-25013100-rear-cThe silver dial and polished hour indices probably make this watch a bit less readable than a black/white combination, but surely this one is more elegant.

Also, the “skeleton” hands are thin, but nevertheless I have never experienced any trouble in quickly reading the time — an important criteria for any watch!


omega-seamaster-120-clasp-cThe original list price of the 2501.3100 Seamaster was, I believe, $1,595.00. I have seen one or two used examples listed in 2009 for $1,700.00. These are not easy to find and for someone looking for a different type of Seamaster with a slightly smaller case, this is it.


The Omega Seamaster 2501.3100 is a unique watch that has served me well, even though I haven’t really worn it very much in the last 11 years. I can highly recommend it for Omega collectors, or for someone wanting to get into Omega watches at a more reasonable price than the new 8500-caliber Seamasters. I ended up selling this one and it found a good home!

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About Rick Korchak

Rick has been an avid watch collector for decades. His first watch was a Zorro manual wind from 1957 and he still owns it today. Learn more about WYCA's Editorial Process.

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