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Omega Speedmaster Professional X-33 Overview

X-33 Overview

Omega introduced the Speedmaster Professional X-33 in 1998, designed in conjunction with aviators and astronauts alike to meet their exacting demands. An updated and improved version followed in 2001. The original version (ref 3290.50.00) is informally known among enthusiasts as the “1st Generation” or “1st Gen” and the replacement 3291.50.00 as the “2nd Gen”; the internals and operation of both models are essentially identical. The crown design was changed with concentric vertical grooves or grip rings for easier operation since the X-33’s crown is pushed/pulled rather than turned. As well, Omega is believed to have strengthened the crown design to address a specific “collapsing crown” vulnerability that affected early 1st generation units.

The X-33 features the in-house developed and unique to Omega 9-jewel quartz crystal controlled calibre 1666 movement, manufactured by Swatch Group cousin ETA (ETA designation E20.321). The movement was designed especially for the X-33 and has never been used in any other model despite continuing contentions to the contrary. Though various brands like Breitling, Bell & Ross and others have used ETA-made multifunction movements similar to those in the earlier Seamaster Multifunction, the 4-pusher cal.1666 and its unique digital display layout and half-step minute hand remain exclusive to the Omega X-33. The cal. 1666 is a non-thermocompensated movement. In a temperature compensated movement, the frequency of oscillation (pulses per second in this case) stays practically the same at whatever temperature the quartz crystal is subjected to [within limits]. A typical watch crystal tends to operate at 32,768Hz with a frequency period of 30.52uS, however regular watch crystals will deviate from this operational frequency depending on the temperature – this is another reason why atomic clocks, which count the cycles of radiation corresponding to the transition between two energy levels within a caesium-133 atom, are still the most reliable with an uncertainty of less than 0.1nS/day.

The X-33’s case and bracelet are made of titanium, a strong and lightweight metal. Titanium’s low reactivity means that it is chemically inert in most circumstances, which gives it excellent anticorrsoive and hypoallergenic properties. Despite the longtime popular myths, strictly speaking titanium is neither stronger nor harder than steel. In fact, on a equal weight basis, steel and titanium have comparable strengths. That is to say half-pound rods of steel and titanium would have comparable strengths. However, the 0.5 pound titanium rod would be much thicker than the steel rod since Ti is much lighter and less dense. If we took 0.5 inch titanium and steel rods, the steel rod would be stronger but the titanium would be far lighter — about 65% lighter — which is one of the things that makes titanium so attractive in many applications where weight is a consideration.

Titanium is not harder than steel and titanium watches will scratch, but some of its chemical properties provide other benefits with regard to scratching. In its naturally occurring state titanium is a shiny metal but reacts spontaneously with atmospheric oxygen to form an exterior oxide layer. This titanium dioxide (TiO2) layer is what gives us the familiar matte-gray lustre and is actually even more chemically inert than titanium itself, which adds to the anticorrsoive and hypoallergenic properties. A secondary benefit is that if the surface is scratched, the titanium underneath will react with oxygen in the air to form a new oxide layer. In this regard, light scratches can appear to “heal” over time if the scratch is not deep enough to scratch through the oxide layer to the titanium below.

Although titanium is the fourth most abundant metal in the Earth’s crust, it seldom occurs in isolated form and usually occurs as oxides in mineral ores. It is relatively difficult to isolate into a form that can be used for manufacturing titanium goods. It is also prone to shearing and tearing during machining, which means that special tools and techniques must be used in machining and metalworking. These difficulties mean that finished titanium products are often considerably more expensive than those made of more traditional alloys despite titanium’s natural abundance.

Technical Specifications:

  • Movement: Omega calibre 1666
  • Type: Quartz multi-function
  • Movement dimensions: 13 1/4 ligne, 30 mm diameter
  • Case Dimensions: 42.25 x 48.50 mm. 20mm lugs.
  • Jewels: 9 rubies
  • Power reserve: 24 months with normal use of alarm and light, or 36 months without use of either feature
  • Battery: lithium, heavy metal (Pb or Hg) free. CR 2320 3v
  • Light: 8 LUX(i)
  • Sound intensity: 80 dB minimum(ii)
  • Water-resistance: 30 meters or 3 ATM(iii)
  • Shock-resistance: 3500 g’s maximum(iv)

To put some of these details into perspective:

(i) One lux is approximately as bright as the lighting from a candle 1 meter away in a dark room. 8 lux would represent 8-times that intensity, i.e. you would be 1/8th of a meter away (0.125m), which in pitch darkness is VERY bright, easily comparable to the lux-output of a mobile phone considering that most mobile phone LCDs output around 5 lux+.

(ii) dB is the abbreviation for “decibel”. One decibel is one tenth of a Bel, named for Alexander Graham Bell. The measurement quoted in dB describes the ratio (10 log power difference, 20 log voltage difference, etc.) between the quantity of two levels, the level being measured and a reference. To put 80dB SPL into perspective, it is about as loud as a hair dryer or vacuum cleaner or 100 times as loud as a normal conversation (60dB). To understand sound properties and perception, further reading is advised.

(iii) To some the stated water resistance rating might seem somewhat basic but it is more than sufficient for the X-33’s intended space and flight applications, light water exposure, and everyday activities. More on water resistance below.

(iv) Shock ratings are often misinterpreted and over-represented. Do not let the 3,500 g rating mislead you into thinking that the watch can withstand a 3500 times gravity impact or a drop from the upper reaches of the stratosphere. In short, while the X-33 is entirely rugged, its shock resistance rating is actually less than the 5,000 g of the mechanical Speedmaster Professional, as is true for most Quartz/LCD watches. In any case, a 100g watch of either mechanical or digital design dropped from a height of 1m will likely experience shock-related damage on impact if we consider a very hard surface like granite or marble floor.

Basic Functions:

  • Hours, Minutes, Seconds
  • Day, Date, Month, Year. Perpetual calendar to 2099AD
  • Alarm
  • Battery end-of-life indicator (second hand jumps in 5-second intervals)
  • Countdown Timer
  • Chronograph – 1/100sec up to 99h59′59″99/100

Special Functions designed for NASA Mission Requirements:

  • Mission Elapsed Time (MT) – up to 999 days
  • Mission Elapsed Time Alarm (MA) – can be set for a specific mission event
  • Universal Time (UT) – including day number or “Julian” date
  • Universal Time Alarm (UA) – second alarm for a specific time & date independent of time zone



TS 186.1998

Speedmaster Professional “X-33“, nicknamed
«Mars Watch», multifunction quartz movement, hybrid display : analog for hours, minutes and second and digital for multifuctions : local time, 1/100 s chronograph with timing capacity of 99h59’59″99/100, enlapsed mission time up to 999 days alarm of mission time, UTC in hour/minute/sec and day number, timer from 99h59’59” to zero, alarm chronograph, perpetual calendar, loud alarm (80dB), powerfull backlight of the display (8 lux), waterproof 50 meters, shock resistant up to 20 G, antimagnetic, -20°C / +70°C operation, precision of ± 0,5 s a day, designed to be used with gloves

Was introduced the 28th of March 1998 to the Houston Space linked with MIR russian station cosmonauts, it is NASA qualified for space shuttle; titanium case with polished steel rotating bezel and pushers, sapphire crystal, back engraved with the seahorse, with black kevelar strap(PIC 3990.50.06) or red Kevlar strap (3990.50.41)



TS 186.1999

ReliftedSpeedmaster X-33 new satin finish rotating bezel with superluminova index at 12‚ and satin finish pushers, new crown with vertical grooves for easier operation, back engraved with the seahorse surrounded by Certified by NASA for Space Missions, new black Kevlar strap (PIC 3991.50.06) or red Kevlar strap (3991.50.41), or titanium bracelet (3291.50)



TS 186.1999

Speedmaster X-33 (see 2001 with caseback engraving Flight-Qualified by NASA for Space Missions and new green Kevlar strap (PIC 3991.50.09)


TS 186.1999

Same as above but special version (12 pieces made only), 10 given to the crew of Team New Zealand (sponsored by Omega), “Defender” of the America’s cup 2003; main characteristics : without hands : made to time races dial with America’s cup New Zealand 2003 (PIC 3992.50.06)



TS 186.1999

Speedmaster X-33, caseback engraved with different US squadrons or NASA, pilots, astronauts or cosmonauts names, titanium bracelet (PIC 3291.52) or Kevlar strap (PIC 3991.52); USA market only

*Data excerpted fromHistory of the Omega Speedmaster as complied and hosted by Chuck Maddox

Water Resistance

A lingering criticism of the Omega X-33 is that it has a water resistance rating of a “mere” 30m. While this is not untrue it is somewhat misguided to criticize an astronaut’s watch for its failings as a dive watch and it is important to keep the intended applications in mind. After all, the original Speedmaster Professional that went to the moon with the Apollo astronauts and survived plenty of ocean slapshdowns had the same “mere” 30m rating, and the Speedmaster is seldom subjected to the same criticisms.

Data previously provided by factory historian Marco Richon of the Omega Museum in Bienne, Switzerland indicates a more robust 50m WR rating. It is not clear if this is a simple mistake or oversight or if Omega may have understated or downgraded the WR when concerns like caseback deformation under pressure emerged. Sources with firsthand knowledge of the model development told us that the watch design before the addition of the hollow caseback had even been successfully tested to a respectable 100m.

While it may be wise to avoid unnecessary water contact with the X-33 and to never use the pushers or pull out the crown under water, the seemingly limited 30m water resistance rating was only predicated on testing showing that the pressure at greater depths risked deforming the thin hollow double caseback required amplify the alarm to the NASA 80dB spec. When it comes to alarm volume and water resistance in a watch, apparently we cannot have our cake and eat it too if we’re using titanium as the case material.

As well, it should be considered that a well-sealed case works two ways in low-pressure environments. A case that does not allow accumulated pressures to dissipate can result in ruptured or ejected crystals in low-pressure environmentd like thodr found at high altitudes and in space, and as such it can be beneficial to have a watch that can make some allowance for “breathing.” And aside from the inability of the watch to continue performing as designed in such a state, foreign object debris (FOD) can present a severe hazard to safe flight if it becomes lodged in flight instrumentation or controls.

In short, while Omega makes other watches that are better suited to swimming and diving, the water resistance of the X-33 is more than suitable for light water exposure, its intended space and flight applications, and for most any everyday task. Owners have also reported swimming and snorkeling without ill effects, but of course individual tolerances for risk may vary and others would consider this unwise. And whatever enthusiast opinions of the “paltry” 30m WR rating may be, the X-33 seems to have been more than sufficient for the Team New Zealand America’s Cup team, who surely got their X-33s more than a little wet. And in any case as one US Coast Guard pilot once related to us, if an aviator has driven his plane into the drink and suddenly finds himself swimming, he has many graver and more pressing concerns than his wristwatch.

The Manual & Packing

Compared to the usual packing one would find an Omega watch inside – the ubiquitous red ‘pleather’ box – the X-33 surpasses in all departments with the ’spacesuit material’ box the X-33 ships in. The watch is also accompanied by a detailed manual, which has been graciously scanned and uploaded to Chuck Maddox’s website for reference. Certainly the packaging has little to do with the quality and functionality of the watch itself, but the distinctiveness of the packaging certainly makes for the pleasant “out of box experience” one would expect when buying a high-quality watch and adds to the uniqueness of the X-33’s presentation.

X-33 Box and accessories. Photograph courtesy of Kieron

X-33 Box and accessories. Photograph courtesy of Kieron

X-33 Pros & Cons


  • Very unique and uncommon watch, with the added cachet of NASA/military pedigree. A no-kidding, real-deal “instrument watch” conceived from inception for real-world usage and designed with input from actual professionals in the field
  • Versatile digi-log multifunction design with many functions
  • Best of both worlds: at-a-glance legibility of analog with digital quartz precision
  • Suitable for most any activity that doesn’t involve lots of water
  • LCD display can be turned off to save battery power
  • Titanium case and bracelet are strong and substantial but still light and comfortable without the “plasticky” feel of some inexpensive Ti watches
  • In addition to strength and light weight, Titanium affords a host of hypoallergenic, antimicrobial, and anticorrosive benefits
  • Domed sapphire crystal causes less reflection than flat crystals
  • LOUD alarm – can actually be heard while flying over engine noise
  • Intuitive, easy to use interface
  • Rotating bezel is very useful in everyday settings
  • Dual-sided anti-reflective coating on sapphire crystal (later Gen2 versions and replacement crystals have AR coating inside only)
  • Some neat features like the way the hands and digital display synch to show the same precise time, the minute hand jumps in half-minute intervals, and the way the second hand pauses for 10 sec. when the light is activated then catches up


  • So many functions that cycling through the entire list can be tedious if you have a pressing need for a specific function (i.e. chronograph, date display etc.). While Omega provided a very clever “quick access” function for the Mission Time function by quickly pushing the 10 o’clock pusher, this function though handy for astronauts is not nearly so useful for the rest of us.
  • Exterior AR coating is vulnerable to visible wear and shows surface imperfections readily, though is easily removed with DIY methods like Polywatch
  • 30m WR is not as water resistant as some competing models. More on the X-33’s water resistance later.
  • The hands’ design minimizes interference with the LCD display but can make low-light reading a challenge without the backlight. Lume performance is acceptable, but mediocre compared to some others and it can be difficult to distinguish between hour/minute hands in low-light situations
  • When new, MSRP was on the pricey side relative to competing models and still is (if you can find them!)
  • X-33 has the same shortfall of many Omega quartz movements where the second hand ticks don’t always fall perfectly on the markers all the way around the dial. This varies, and not all users report this complaint.


  • Quartz controlled movement will be a pro or con depending on whom you ask in this price range. But the performance of quartz is hard to argue with for its intended application.
  • Same for the dual-sided AR coating – it improves legibility but is much less durable and vulnerable to scratching than the tough sapphire underneath. (Inside-only AR coating was implemented on later Gen 2 models and later crystals installed as replacements. Thanks to Jude Hasken and Fleming for the helpful correction!)

LCD Display Circular Polarization

Special thanks to Bruce Redding, Gaijin, and the posters of WatchUSeek for the information in this section!

A little known and unpublicized feature of the X-33 recently uncovered is that the LCD display incorporates a special feature intended to prevent interference with polarized optics. Liquid Crystal Displays (LCD) work by polarizing the light of certain sections of the display in particular directions. Most conventional LCD displays have the light coming from them polarized and oriented in a single direction. When viewed through polarized sunglasses, which filter light in a way that only allows light oriented in a particular direction to pass through, an LCD display can “black out” when viewed at orientations in a direction close to perpendicular
to the filter. This is the reason most cellphone and car navigation displays are unviewable at certain angles when wearing polarized sunglasses.

LCD manufacturers typically
attempt to minimize the impact of this effect by orienting the polarization of the LCD display in an advantageous direction, but Omega went a step further. By adding a quarter-wave plate and orienting it in a deliberate manner the polarization of light from the display becomes directionless and won’t be blocked (completely) by polarized filter.

Suunto CORE with conventional polarized LCD display is “blacked out” by orienting a polarizing photographic filter perpendicular to it.

The X-33 on the right remains visible however no matter how the filter is oriented.

See this excellent WatchUSeek thread for more details.

Photos by Gaijin

Though polarized glasses are typically not worn when flying because they can interfere with modern instrumented “glass cockpit” Heads-Up Displays (HUD) and layered glass heated cockpit windscreens, the addition of such a feature that adds to the cost
is notable even if not very necessary. And indeed, NASA may well have some use for the feature unneeded by civilian pilots.

>>> Proceed to Part 2 – Gen 1 and Gen 2 X-33 >>>

14 Responses

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  1. Antonio Reynoso says

    I have an x-33, but i need to get a titanium pulse because mine has a leather pulse.

    I appreciate your information



  2. Frank says

    Great review but not reflective of my experience. Bought this watch in 2000 and since then it has required module replacements TWICE! After the last service (in 2008) I was told by Omega that the watch is no longer waterproof because the case buckled, which apparently happens only to the x-33. After the last repair, I no longer wore this watch because of how fragile it was. Upon discovering the battery was dead recently, I brought it in for a replacement and was told that it needed a new module again because the electronic display was no longer working, making this the third module replacement.

    This watch is complete garbage. Omega puts out garbage irrespective of the fact that NASA uses them. Actually considering the current state of play – NASA use is actually an anti-endorsement. Will never buy another Omega or anything else from the Swatch Group. Would definitely NOT recommend.

    • tom says

      Hi Frank,

      I have exactly the same experience with mine, pure rubbish. They put in a new module two years a go and now again it is rusty inside and need to replace it. As usual just 2 months out of guarantee. I have no already spend half the value of the watch on repairs. Did you have any action taken towards Omega. I am at least planning some complaining procedure and I am assembling information. Thx Tom

  3. Nate says

    Great review but must be fairly old as several other watch makers now use the ETA E20.321 movement as a matter of proven fact.

  4. Lloyd Crawford says

    I’m sorry to hear that other owners have had problems with their X-33, I have to say I’ve had no problems other than having to replace batteries. I love the watch, love the design, the legibility, the functionality and the cachet of sporting a NASA approved timepiece. The alarm is really usefully I time my runs with the stopwatches I use the dual time feature when traveling and the backlight is amazing. The bezel does pick up light scratches easily, but that’s titanium for you and I knew that would be an issue going in.

    • Fernando says

      I bought X33 2005 and never was accurate between digital and nail time, I have been experience some fault recently. At the moment it is on Omega service, expecting big quote for fixing.
      I am wondering if it will be good or not invest on repair.


  5. Wilson Orisha says

    I have bought the X-33 in 2009 but can’t find any good repairs on it and now the Light has spoiled while changing th battery.

Continuing the Discussion

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  3. Speedy Tuesday - A FratelloWatches Reader And His Space Watches linked to this post on 04 February 2014

    […] Next we have this Omega Speedmaster Professional X-33 ‘Marswatch’ from the 1st Generation. In fact, we covered this particular watch from our reader Hans before (click here) as it was owned by a former NASA employee who used it during his work for the space agency. The Omega Speedmaster Pro X-33 was available in two different versions, as the 2nd Generation had a brushed bezel and pushers and a different type of crown that was easier to grasp. Also, the digital quartz movement caliber 1666 was replaced at some point with a thermo compensated version caliber 1666D. A lot of X-33 information can be found in this excellent write-up from the guys over at […]

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    […] overview of all X-33 models and functionality can be found on the ialreadyhaveawatch website, here. Again, please get in touch with us if you have an Omega Speedmaster X-33 2nd Generation. We would […]

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