The TimeZone Omega Forum FAQ page is a place to learn answers to questions that are frequently asked on TimeZone. Usually a person new to the subject of watches or the hobby of watch collecting has to spend uncounted hours searching for answers or asking questions in forums. The goal of this page is to give you a quick overview on the basics. For more in-depth information please take a look through the companion TimeZone Omega Forum Links Page.

In a sense this page will always be under construction, as people ask questions all of the time and if a question gets asked often enough one of the authors of this FAQ will say "That one really belongs in the FAQ!". And it will be added.

If you have a question/answer that you feel belongs here please post in the Omega Forum or contact Bill Sohne, TimeZone Omega Forum Moderator; or contact either Damon Michau (who also is a TimeZone Omega Forum Moderator) or Chuck Maddox both of whom authored most of this FAQ...

Frequently Asked Question Page  

  1. Introduction
    1. What is this?/Why does this exist?
    2. Link to's FAQ...
    3. I am confused by watch terms, What do I do?
  2. Dealer Issues  
    1. What is the difference between authorized and "gray market"?
    2. How much can I expect to pay for a new watch?
    3. Resale value: Authorized Vs. Dealer Gray Market?
  3. Movement Issues  
    1. Automatic or Quartz: Which is better?
    2. Active activities & Mechanical Watches, What's suitable?
    3. How often should I wind my mechanical watch?
    4. How do you start a fully unwound Automatic watch?
  4. Care Issues:  
    1. Water Resistance Issues:     
      1. How deep can the watch actually go? 
      2. Will chlorinated or sea water hurt my watch?
      3. Okay to wear my watch while I shower/hot tub?
  5. Maintenance Issues:  
    1. What maintenance does my Omega need, and how often?
    2. What is the best position for time regulation?
  6. Repair/Service Issues:  
    1. Who should I send my Omega to for service?
    2. Should I send my watch to Omega or a local watchmaker?
    3. Omega says they don't have parts for my vintage Omega, what now?
  7. Bezel Questions:  
    1. What does a unidirectional bezel do?
    2. Can I change the insert on my Seamaster?
    3. How do I use a Tachymetre/Decimal/Telemetre/etc. Bezel?
  8. Deciding on a Model...
    1. Which one: Seamaster or GMT?
    2. Which one: full-sized or mid-sized?
    3. Which one: Stainless or Titanium?
  9. Specific Model Questions:  
    1. Seamaster Professional     
      1. How does the helium release valve work?
      2. How does Omega modify the ETA Base Movement for this watch?
    2. Seamaster Professional Chronograph-Chronometer (SeMPC)
      1. How should I set my watch winder up for a Seamaster Pro Chrono?
    3. Omegamatic     
      1. How does the Omegamatic work?
    4. Speedmaster (General)
      1. Which is the best Speedmaster Movement?
    5. X-33 Speedmaster     
      1. How do I use the non-listed shortcuts of my X-33?
    6. Speedmaster Professional Moonwatch
      1. Why doesn't the Speedmaster have sapphire crystal?
      2. Why wasn't an Automatic Watch chosen by NASA?
    7. Speedmaster Moonphase
      1. What time does the moonphase indicator change?
      2. The Moon's current phase is...
  10. Serial Number Issues  
    1. Where is the serial number on my Omega?
  11. Are These Defects?  
    1. Seamaster Pro automatic is running fast/slow...
    2. Chronograph hand alignment...
    3. Hour register on my Chrono doesn't always stay zeroed when not in use...
    4. Seamaster Professional bracelet shows scuff marks...
  12. Insurance Issues:  
    1. Insuring a watch without serial numbers/warranty card...
    2. Determining a Vintage watch value...
  13. Bracelet/Band/Strap Issues:  
    1. Where can I get an Omega band?
    2. Which one: strap or a bracelet?
    3. How do I remove links from my bracelet?
    4. Where do I get straps/bracelets/parts for my Omega?
  14. Informational Number's/Sites:  
    1. What's the contact number/address/email for Omega in Pennsylvania?
    2. Are there other Authorized Omega Service Centers in the U.S.A.?
    3. Does Omega have a web site?
    4. Does Omega have an Official FAQ?
    5. My Omega's serial number is xx,xxx,xxx. Can anyone tell me more about it?
    6. How do I contact Omega in Switzerland?
    7. Is there a time-line of Omega's achievements?
  15. Other Common Questions:  
    1. Could a winder for my automatic watch(es) damage them?
  16. Important Disclaimer


What is this and why does this exist?

This FAQ, like most FAQ's, was created with the purpose of qualifying and quantifying some of the most commonly asked questions and providing suitable answers that can be pointed to when they crop up. It is the work of a small number of devoted individuals who otherwise would likely be answering these questions by hand every time they are raised.

It is important to note the Disclaimer at the bottom of this document and to state that has their own Omega FAQ and should be considered canon (or the preferred source of authoritative information)... In addition, if you are interested in learning more about specific topics please look through the companion TimeZone Omega Forum Links Page for more in-depth essays and information.

I am sometimes confused by all of these watch terms, What do I do?

The TZ Classic 0183 “Glossary of Frequently Used Terms” by Jaeger is a good start...

Dealer Issues

What is the difference between authorized dealers and the "gray market"?

Authorized Dealers

Gray-Market Dealers

Authorized dealers obtain their watches directly from the manufacturer or the manufacturer's authorized agents. An authorized dealer is able to offer the manufacturer's warranty, plus all official papers or certificates, warranty cards correctly filled out, booklets, and any other materials intended by the manufacturer to accompany the watch. Authorized dealers have access to manufacturer literature, support, training, and parts.

Gray market dealers are essentially non-authorized re-sellers. Gray market dealers obtain their watches from a variety of sources all over the world, and they cannot offer the manufacturer's warranty. Because "Gray's" bypass authorized channels, they usually offer lower prices than authorized dealers. Some gray market dealers offer their own warranty, however you can never be sure about the quality of the person who will work on the watch, their training, or their access to parts, should the watch require repair. Some gray market dealers do not offer all boxes and papers that originally accompanied the watch. Some gray market dealers deface watches by removing the serial number. This can make the watch impossible to trace if stolen, and it can render the watch uninsurable. In some US states, removing serial numbers is illegal, and a watch with the serial number removed can be presumed stolen. For more information on the gray market, please take a look an Bill Mattocks TZ Classic 1435 :Gray Market Watches

How much can I expect to pay for a new watch?

Discounting practices vary widely from country to country, but in some countries, including the USA, many authorized dealers will discount their prices from the list price, if you negotiate. Some dealers will discount more than others, and some will not discount at all. Where offered, discounts depend on several factors, including your geographic location, whether you are buying from the dealer's stock or special ordering, the model watch you want to buy, demand for that model, whether the model has been of will soon be discontinued, the dealership's finances that day, whether you are a regular customer or one time buyer, and your method of payment (Cash/Credit Card). If you are purchasing from a dealer in another country, currency exchange rates can also play an important role. The time of year can also affect pricing. Shopping between Christmas and New Years is typically beneficial as stores are looking to make sales before the end of the year. Shopping after traditional gift giving holidays, like Mother's day, Father's Day, graduations, and Valentine's Day, can sometimes produce better deals as well.

Among USA dealers who will discount, you can typically negotiate ten to twenty percent off list with little or no effort. Twenty-five to thirty-three percent off might be achieved under the proper circumstances. Larger discounts are rare, usually given only for close-outs, discontinued items or going out of business sales. Shop around and see what you can find... prices will likely vary.

What factors affect resale value?

Resale value is affected by several factors. These include the condition of the watch, whether it is fully intact, running properly and original (e.g. has all serial and other identifying numbers in place), whether you have all original boxes and papers, your location and that of the buyer, the service history, the desirability and rarity of the watch, and the nature of the buyer. When you trade a watch in to a dealer, you will likely only get wholesale value, just as when you trade in a car, after all the dealer has expenses to meet and still show a profit. You can typically get more for a watch by selling it yourself to a "retail" buyer.  

Movement Issues

What's the difference between an automatic and a quartz watch? Which is better?

Automatic/Manual Wind:


An automatic is a testament to the ability of watchmakers to put hundreds of little parts into a watch case and get them to work all together with close tolerances just to tell time. An automatic watch depends upon movement to power it while a quartz watch uses electricity for its power, typically a battery. It's a matter of opinion as to which is better... But all of those little parts mean that there are more things to break. Manual watches do not have a rotor to wind the mechanism, and rely upon the user to wind them.

An automatic/manual is usually more expensive to repair than quartz, but if you take care of the watch, you shouldn't have to worry about this. The nice thing about an automatic/manuals is that should water get into your watch, it won't kill it unless you don't have it serviced after the leakage occurs. An automatic/manual watch does not typically keep as accurate time as quartz would, and if you're an accuracy nut, this could get annoying. Another drawback is that you will likely have to reset your watch every now and then, which causes wear on the gaskets and increases the chance of water getting into your watch. Also keep in mind that every time you let the watch run out of power, you will have to reset the time.

An automatic can take some beating, but not as much as a quartz. Manual wind watches are usually somewhat tougher than automatics as they don't have the rotor spinning in the case. If you drop an automatic, there is a greater chance that something will be damaged. However, if you take care of an automatic/manual, it will last you a lifetime and you can pass it on to your family. Also, should you decide to sell your watch, an automatic/manual is more likely to fetch more money than quartz will. Also, an automatic's second hand sweeps nicely around the dial in a continuous motion. Some people think that an automatic has more of a "soul" than a quartz watch, as it depends on the motion of your arm to power it. Some feel that since a Manual Wind requires the owner wind it it's more symbotic.

A quartz watch is a testament to humankind's technological know-how that permits the etching of a wafer of Silicon (sand) with hundreds, thousands or even millions of electronic components, passing a small amount of current through it, and measureing time even more accurately (typically) than a mechanical watch does. A quartz watch requires less maintenance than an automatic. The only maintenance that the watch will typically need is a battery change and to have its gaskets changed annually if it's around water. It is very accurate, so this will stop you from having to unscrew the crown and cause wear on the gaskets. The down part to quartz is that if water gets into your watch, it usually means death to the movement. But the plus side to this is that it will be relatively inexpensive to replace a quartz movement than an automatic. The battery inside a quartz watch can leak acid and corrode the movement. This will usually happen if you let an expired battery to sit too long inside a watch after it dies. Thus it is a very good idea to have a quartz watch serviced immediately after its battery goes flat.

The great thing about a quartz watch is that it can sustain one heck of a beating and keep on ticking. So if you're rough on your watches, this is a major point that you should take into consideration when choosing which movement is best for you. Another great thing about a quartz watch is that you can take it off and let it sit on your desk for long periods of time and it will still be ticking when you decide to wear it again. Unless the battery dies, that is.

A quartz watch should last you all of your life if you take care of it,. Some people argue: why buy an expensive watch and take the risk of your battery no longer being available? This is a valid point, but if the past is any indication of the future, Omega will continue to support your watch for quite some time. The second hand on a quartz watch moves in one-second increments.

There is no "one better watch". One type of watch may better for you than the other. The best person to make that decision is you.  

Active activities and Mechanical Watches, which are suitable?

Most modern watches are shock protected. In fact a TZ Omega Forum regular (Scottpalmy) inquired about this issue to

After purchasing a SMP several months ago I Emailed vintage Info at Omega to check on date of manufacterer, and also asked:
"... can you confirm whether you recommend wearing or not wearing the Seamaster professional whenplaying golf."

The reply from Omega:

Your watch, as every other OMEGA, has a shock-protected movement, hence normal sports activities are not endangering the functions of yourtimepiece.

thank you for having selected OMEGA !

best regards

John R. Diethelm
Vintage Information  

So, if you'd like, you can contact and inquire about your watch. Or you might want to play things more conservatively... 

With a manual wind the activities that would be of concern would be high contact/collision sports like Football, Baseball, Polo, and the like. High recoil activities such as target and trap shooting or hunting should not be a problem unless you wear the watch on your primary shooting hand (right wrist if you're right handed, etc.). With shooting most of the recoil goes into the strong or primary shooting hand. If you are shooting pistol your wrist would typically be on off hand, with rifle and shotgun your watch hand would typically be on the fore grip and not as subject to physical shock as your trigger hand would be as it is closer to the shoulder stock.

Of course if your active activities include operating a jackhammer an LCD Quartz watch like a G-Shock is recommended. That's what they are made for. In all fairness an expendable, inexpensive LCD Quartz watch is almost always a better idea for high-risk activities than a manual or automatic watch. 

For automatics an additional concern to the above are activities that generate a great deal of torque or inertia at the wrist/hands... Activities such as Golf, Tennis, Polo, Baseball, Jai-Lai, Lacrosse, and the like are likely to cause the rotor to spin rapidly which is generally not a good idea... Sort of like running your car close to it's red-line at full throttle.

Many mechanical and automatic movement watches have endured long stints in extreme active use and survived no worse for wear. A number of movements are renowned for their toughness. These include the Omega c.321, c.861, Lemania c.1341 (Omega c.1040 and c.1041), c.5100 (Omega c.1045), Valjoux c.72 and c.7750, movements. There are probably others. In all instances in these cases the watches in question were: quality made, robust movements (not a lot of delicate complications), and in good mechanical condition and well serviced.

However, it is not advisable to wear an automatic for the "high torque" activities mentioned above, a more robust manual wind or a quartz would be better choices. I would be more concerned about wearing an Automatic watch when shooting than I would be a manual wind, not only because of the rotor but also because there is more to go wrong typically.

Additionally it is not advisable to any vintage watch you were concerned about repairing or finding replacement parts. Certainly c.861 based watches are safe as they remain in production and spares are plentiful, but it would be unwise to wear a c.321 or a Valjoux c.72 because of the increased difficulty of obtaining proper repair parts since they have not been in production since the late 1960's. The same would apply to a Tuning Fork watch even though they are tough watches, because they are uncommon, have not been in production for many years and finding parts is increasingly difficult.

Wearing a chronometer (like a SeMPC or a Speedmaster 125) should also be avoided in order to preserve their accuracy... I'd also resist from wearing a limited edition or limited production watch for the same reasons.

How and how often should I wind my mechanical watch?

Watches typically only wind when the crown is rotated so that the top part is moving towards the 12 o'clock position. Some people only wind the crown towards the 12 o'clock position and then turn the crown back a few clicks so that the oil that is used on the winding train doesn't sit on all of one side of the gears. However, the mechanism is like a Ratchet and it is intended that you can wind the watch with a back and forth motion too. Some people use the back and forth method. Either way is fine...

Wind the watch (either method) until you feel increased tension. Do it slowly the first couple of times you wind the watch so that you can sense it. For more information pertaining to the crown we recommend Walt Odet's TZ Classic 57 : “Some basics in handling the crown...

Many people feel that it's important to only wind the watch once a day. There is a certain point to this (letting the watch wind and unwind) as you operate the watch throughout a range. However, if you might forget to wind the watch you may overstep the power reserve. This happened often during Gemini/Apollo space missions, the astronauts would get so preoccupied with tasks that they would forget to wind their watches and find that when they needed them they had wound down. So many people "top-off" the watch in the evening or a couple of times (say morning, midday, and at night before retiring for bed) during the day. Doing so would not hurt the movement... Letting the watch run throughout it's "range of motion" or power reserve from time to time is probably a good idea. It might be a good idea to let your manual wind watch wind down over the weekend and wear a different watch during the weekend. This will let the watch run over a full range of motion on a weekly basis.

It is advisable to be careful winding the watch until you become comfortable with the procedure, then work into a routine you are comfortable with...

I own an Automatic SeMP. How do you start it up when it's fully unwound?

Unscrew the screw-down crown to the first position, and do 40 back-and-forth winds on the crown. Then set the time and the date (as long as the watch is not set to a time between 8pm and 3am). This should power the watch so that it won't stop. Wear the watch normally after this for the rest of the day.

If you wind the watch and wear it all day, you should have a full power reserve at bed time. You can then choose to wear the watch to bed or not.

Care Issues:

Water Resistance Issues: 

With a water resistance rating of __ meters, how deep can the watch actually go?
A general rule of thumb on watches when it comes to water resistance rating is:

Under 30m =

Well, just try not to get it wet, ok?

30m-50m =

Bathing, hand/dish washing, etc.

100m =

Swimming pool or shallow swimming [i.e. less than 10m],

300m =

SCUBA diving,

Over 300m =

Deeper diving.

Will chlorinated or sea water hurt my watch?

If your watch is stainless steel, chlorinated water will not hurt the watch. It's not a good idea to expose your gold watch to chlorinated water, as the chlorine can cause pitting of the gold. If you do take your watch in a water environment often, have the gaskets checked twice per year as chlorinated and sea water will cause them to lose their effectiveness faster.

However, it is a good idea to rinse your watch in plain tap water (distilled would be better) after swimming in a chlorinated pool or salt water.

Is it okay to wear my watch while I shower (or hot tub, etc.)?

There are some very good reasons not to.

Most people use soap or detergent (in shampoos) in the shower. Many soaps or detergents contain abrasives, so what you are essentially doing is putting an abrasive in contact with your watch's crystal and finish. The effect of such abrasive is not good, so why risk it?

Secondly, the primary purpose of soap or detergents is to get water and oils to mix with one another so that they can be removed (by the combination of soap and water) from the body. So what you end up with is a mixture of soap/detergent, water, oils and dirt. Unless you are able to completely able to rinse this out from all of the tiny cracks and crevices of your watch's case, bezel, bracelet, etc. this slurry of materials will accumulate in nooks and crannies on/in your watch.

Third, heat expands, cold contracts. Different materials expand and contract at different rates. So it makes sense that if you move from a 68F room temperature into 100F shower water quickly, the case and case back may expand at a different rate than the rubber gaskets do, which may cause problems with water resistance.
Now, none of these items will cause a significant depletion of WR in a watch if you forget to take off your watch occasionally when you hop into the shower. But why put the watch at risk unnecessarily?

Maintenance Issues:

What kind of maintenance does my Omega need, and how often do should I have it done?

If you have a mechanical or automaticmovement, you should have it re-oiled every five to ten years depending upon how much wear your watch gets.

If it's a quartz watch, you should have the battery replaced as soon as it starts to die.

With either kind of movement, if your watch is around water often, you must have its gaskets checked annually. If it's not around water often, you should have its gaskets checked every two to three years.

What is the best position to leave my watch so that it gains or loses the least amount of time?
Each watch is different when it comes to this. Whether its dial-up, down, crown left, or right, depends entirely on your watch. Experiment with the different positions each time when you take your watch off, and find out what works best for your watch.

Repair/Service Issues:

My Omega needs service; to whom should I send it?

If your watch is under warranty you should have it serviced by Omega in the country you reside, or by an authorized Omega dealer or service center. If you purchased your Omega and the watch is under a gray market warranty you should send it to the place you purchased it from. If your watch is out of warranty and you have a watchmaker in your area that you trust, you have the option to use him or her. Typically this would be cheaper than sending it to an Omega service center. If you want to send it to an Omega service center, the best one is at the factory in Switzerland.

Should I send my watch to Omega for repair/battery/waterproofing, or have my watchmaker do it?

You can do either one. Omega will give you a one-year warranty on their warranty service, and most watchmakers have a warranty on their work also. If you have a watchmaker that you know, and trust, you can take it to him, and that will probably be less expensive then sending it to Omega.

I have a vintage Omega, and Omega says that they don't have parts for it. What do I do now?

This is the sad part of owning vintage watches, but there is still hope. You can either find the same movement and pull the parts out of it that are needed, or you can try finding a watchmaker who knows how to make parts. You can find a good list of watchmakers on the
NAWCC web site.

Bezel Questions:

What does a unidirectional bezel do?

Its prime purpose is to keep track of time under water. It is unidirectional so that if it gets bumped, it will only lessen the time left for diving (i.e. bumped from 30 to 29 minutes). It can also be used as a timer, elapsed time, and time zone indicator.

Can I change the insert on my Seamaster from blue to stainless steel, or vice-versa?

Yes you can, but it is a tricky job. Most watch makers will tell you that you should buy a new bezel, because if the insert gets bent while installing the new one, it will put a permanent white line on that bezel insert. If you want to change the color insert, send your watch to an Omega service center near you.

How do I use a Tachymetre/Decimal/Telemetre/etc. Bezel?

Two good places to learn this are the TimeZone Classics created by the co-author of this FAQ entitled
1027: The Definative Answer to 'How Do I Use The Tachymeter'” and 1178 How to use 4 different types of Bezels....


Deciding on a Model...

Which watch should I get: Seamaster or GMT and which one is better?

Do you have a need for the GMT's features? If so then you should strongly consider it. The GMT omits the Helium Escape Valve, but has the same Water Resistance as the regular Seamaster. Otherwise, go with the one whose looks you prefer. They're both great watches, and you can't go wrong with either one. The best one is the one that makes the most sense for you.

Should I get the full-sized Seamaster Professional or the mid-sized one?

This is a dilemma that almost everyone that has purchased the watch has faced, and the answer is to get the one that you think both looks and feels best on you. Go to an authorized dealer, and wear the type of clothes that you wear on a day-to-day basis. Try on both watches, and look in a mirror and see what you like best. The full-size Seamaster may look big at first, but you will probably get accustomed to it.  

Should I get the Seamaster Professional Chronograph in stainless steel or titanium?

Go for what you like best. The titanium is much lighter than the stainless steel, but it also scratches somewhat more easily. To give you an idea of the difference, a Stainless Steel Seamaster Professional Chronograph tips the scales at 206 grams, while its Titanium counterpart weighs a mere 142.7 grams - a savings of over 60 grams or more than two ounces.

Specific Model Questions:

Seamaster Professional: 

How does the helium release valve on my Seamaster work? Can I open it on land?
The helium release valve works by letting helium out of your watch, and nothing else in. This only comes in handy when you are in a helium-saturated environment such as a dive bell. You can open it on land, but make sure you screw it back down before you submerge it in water. Leaving it open while the watch is under water can let water into the watch. Note: This system is consistant with the Seamaster Professional Chronograph - Chronometer as well...


How does Omega modify the ETA base movement for use in this watch?

In addition to polishing the components and adding the Geneve Wave decor, Omega replaces the rotor with an Omega Specific (only) rotor that rides on a small ball bearing. They change the automatic bridge with a their own gear-train and endshake corrector. Which in turn, reduces the height difference between the auxiliary reverser and rotor. This also allows the oscillating weight's gear to mesh more precisely with the click wheel. This modification reduces the rotor's play during movement, and also prevents friction against the plate. On a standard ETA ebauche, a metal seating is used to hold the barrel in place. Omega replaces that, and uses two jewels to hold the barrel in place. This improves the constancy of the force flow and ultimately produces a more accurate movement, and adds about 2 hours to the power reserve. And to top all that off, add pure gold inlaid engraving for the writing.

Seamaster Professional Chronograph (sometimes referred to as SeMPC): 
How many turns and in which direction should I set my watch winder for a SeMPC?

Graham passed this information to us:

  • Watch-winder with slow rotation : one full round per minute. To be fully wound, it will require around 20 hours of rotations.
  • Watch-winder with fast rotation : four full rounds per minute. To be fully wound, it will require around 5 hours of rotations.
  • One direction rotation, clockwise direction It is not essential to use a watch-winder for your Seamaster watch. Your watch should be wound once a day, if possible in the morning. As mentioned before if the watch is fully wound, its power reserve will be around 44 hours.
We hope that you will be wearing your Omega watch with much pleasure for many years to come.

With kind regards,

Maria M., OMEGA Ltd Customer Service

This was sent to me on June 15, 2001 Ihope this helps -- Graham
Note: These instructions should be universally applicable for the ETA/Valjoux 7750 base movement which is also used in certain Omega Speedmaster lines. Thanks Graham!


How does the Omegamatic work?

The movement in the Omegamatic is a hybrid movement that uses the same concept as an automatic movement: a rotor which rotates when the wearer moves, to generate energy. However, instead of storing the energy generated in a metal spring, the Omegamatic movement's rotor moves a micro generator that creates electrical energy which is stored into a capacitor. Then this energy is transmitted to an integrated circuit, which contains a quartz crystal whose oscillations are driven by the integrated circuit. The integrated circuit then sends the necessary impulses for the functioning of a stepping motor which drives the hands.

An Omegamatic can also create electricity by turning the crown of the watch.

The benefits of such a movement is that you have the best of both worlds: Quartz Accuracy, without the need to change a battery every year or two.

Speedmaster (General):

Which is the best Speedmaster Movement?

Depends on your tastes and as usual with such answers it will vary from person to person...

The c.321 is the movement most sought after by collectors because it was the original Speedmaster movement, was the movement used in the first watch worn on the moon as best as anyone has been able to determine.

The c.861 and it's variants (c.863, c.1861, c.1863, etc) have their adherants as well. It's a strong robust movement with many things to go for it, among them: higher oscillation frequency hence theoritically more accuracy, fewer components leading to fewer production processes (costs) and simpler repairs and adjustments. The c.86x series are 17 jewel movements with all steel parts and Gilt (gold colored plating), whilst the c.186x has an additional jewel, a single nylon part and a Rhodium plating to the movement.

There are also many fans of the Lemania 5100 movement (c.1045 in Omega terms) and even some fans of the c.1040/c.1041 movement which is very similar to the c.1045 and offers many of the same features.

It all depends on what you are after. In theory, the c.861 and it's ilk should be a little more accurate than a c.321 but there isn't much difference between the two in the real world...

X-33 Speedmaster:

How do I use the non-listed shortcuts of my X-33?

The non-listed shortcuts on the X-33 are: Alarm, Mission Alarm (MA), Universal Alarm (UA), Count Down Timer (CDT). They can all be set by pushing in the crown and holding it for 3 seconds until the function flashes. This allows you to set these functions without pulling out the crown, which can be hard if the watch is on your wrist.

Speedmaster Professional Moonwatch:

Why doesn't the Speedmaster have sapphire crystal?

Omega uses the plastic/acrylic crystal because it is shatterproof. While sapphire is scratchproof (virtually), it isn't safe at very intense pressure levels. An astronaute would have a very HUGE problem if his sapphire crystal shattered at 0 G. That's why it's used on the Speedmaster Pro and not on the regular Speedmaster's, it's intent is to be a professional Pilot/Astronaute's watch, in that respect it does its job admirably, IMO.

Besides, a Hesalite (plastic/acrylic) crystal can very easily be polished out, but if you ever scratch/chip your sapphire crystal, you will have to replace it or live with it as Sapphire is so hard it's exceedingly difficult to polish out any scratches...

Special thanks to Marc (Time2Watch) for his contribution to this answer...

Why wasn't an Automatic Watch chosen by NASA?

One of the reasons that NASA chose a manual wind watch for space flight crew use was that they wanted a chronograph and automatic chronographs would not be perfected until 1969. In addition NASA had the mistaken belief gravity needed to be present in order to cause the Rotor to work.

As Newton described objects at rest tend to stay at rest unless acted upon by a force. When the watch is moved, the rotor wants to stay put. Since its center of mass (somewhere in the middle of the rotor plate) is not its center of effort (the rotor shaft), it spins. Along the way, it winds the watch. However, what is important in this equation isn't gravity, but rather Inertia...

To see a demonstration of how Inertia works on a automatic watch take any display back watch automatic or an automatic with the caseback off and hold the watch with the dial down.... One can easily set the rotor spinning moving the watch in a circular motion. Gravity doesn't play a significant part, because the rotor is more or less level gravity isn't acting on it in a significant way. The inertia from from moving the watch around is what moves the rotor and winds the watch. Inertia is a magical thing.

So, Automatics will work in Space. In fact if the watchmakers had been 5-10 years earlier with the creation of the automatic chronograph complication, the moonwatch might have sported a Valjoux 7750, a Lemania 1342, or a Lemania 5100 under the dial instead of manual wind movement.

Special thanks to Thom Dyson for his contribution of this answer...

Speedmaster Moonphase:

What time does the moonphase indicator changes on my Speedmaster Moonphase? It doesn't seem to change at the same time as the date...

According to M. Alejandro de la Torre who has experience in assembly and disassembly of moonphase chronographs, "the traditional moonphase disc, has 59 teeth advancing at the rate of 1 tooth per day (reflecting two 29.5 day moon cycles on the disc). The time that this happens, I am unaware of on the Lemania chronograph. However on the Valjoux 7751, occurs between 3 am and 4 am. I am almost certain that the Lemania movement in the new Speedmaster Moonphase Replica has this type of moonphase mechanism."

Alex has a wonderful page with the story of his work on making a totally unique version of the Valjoux movement Speedmaster Moonphase for him self that is beautifully illustrated... Please link to it from here...

What is the Moon's current phase?

The Moon's current phase is:
This image updates every 4 hours.
If display is black, the moon is new.
by Virtual Reality Moon Phase Pictures


A lunar months worth of
phases in a few seconds:

The lunar month is approximately 29.5 earth days. This is the reason why many religious holidays which are based on the position of the moon, like Easter, Passover and Ramadan, occur at different times from year to year.

The moon rises approximately 55 minutes earlier each day in it's progression around the earth.


Serial Number Issues:

Where is the serial number on my Omega?

All newer Omegas have the serial number on the case back. Most of the Seamaster's, Dynamics, De Villes, and Speedmaster's have it on the seven o'clock lug, while some are reported to be on a different lug. Constellations have their serial number on the screw on case back. Older Omegas have serial numbers on the movement.

The serial number is actually the number that is on the movement, and the series of numbers is not connected to any particular line of watch. Every movement Omega makes is numbered sequentially and engraved on the movement.

Are these Defects?

My new Seamaster Pro automatic is running a few seconds fast/slow; what should I do?

Relax. Like most mechanical devices, a new watch has a break-in period that lasts for about a month or so. During this time, your watch is distributing the oil around, and is breaking in its gears. Its accuracy will vary by a few seconds during this time, but it will eventually settle down. The C.O.S.C. standard is +6/-4 seconds a day. If it's running way over that, return your watch. There are a number of TZ Classic Articles on C.O.S.C. and watch accuracy including:“
0139: The Confusing Language of Watch "Accuracy"” by Justin Time”, “0267: Info about COSC testing” by Paul Schliesser, “1111: Reading and Understanding a COSC Certificate” by Mike Disher and for information which Swiss manufacturers make the most Chronometre's have a look at “1820 : Contrôle Officiel Suisse des Chronometres (C.O.S.C) Numbers 1999-2000” by FAQ co-author Chuck Maddox.

The chronograph hand on my Speedmaster Professional doesn't sit exactly on the twelve; is my watch defective?

This is not uncommon, and it is not a major problem to worry about. Typically this occurs when a watch hasn't been serviced in a while and the remedy is to have it attended to when you choose to have the watch serviced (Cleaned, Lubricated, Adjusted, often called CLA). If your watch doesn't reset to "zero" geting this item adjusted but not getting the watch cleaned and lubricated at the same time won't necessarily prevent the misadjustment from reoccuring. If you can live with the watch being off by a couple fifth's of a second, it won't harm the watch to continue to use it until it's a convenient time for you to be without it while it's being serviced. When you take the watch in for servicing, explain all of the issues you note with the watch, so that the watchmaker can attend to each of the items noted.

The Hour Register on my Chronograph doesn't always stay on the twelve when the chronograph is not in use; have I broken my watch?

This is typically called "Hour Register Creep" and does occur on certain types of chronograph movements used by Omega (Lemania c.321 & c.861, and those using Valjoux 7750 & 7751 base movements) throughout the Omega product line as well as other companies using these movements. Thus this is not an issue that is restricted to any one product line (Speedmaster, Seamaster) but can occur with any watch using these movements. However, it seems that watches using the Omega caliber 1045 (base movement Lemania 5100), 1040 and 1041 (base movement Lemania 1341) do not seem to suffer from this malady, or suffer at a much much lower rate than the previously mentioned movements.

This problem happens because a spring that causes tension on this register gets slightly out of alignment. Sometimes carefully resetting the chronograph can minimize this problem from occurring, until you decide to have the watch serviced. Another workaround is to simply press the reset button before activating the chronograph function. Typically it's not worth the time and expense to send the watch into Service for just this problem if the watch is out of warranty. However, you should ask for it to be repaired the next time you have your watch in for periodic service... If you ask the Watchmaker to look into this the cost for repair shouldn't be much if any greater than a typical service (clean, lube & adjustment)...

My Seamaster Professional's bracelet shows scuff marks already. Is there any way to stop it from happening, and can I remove the ones that are already there?

The clasp on the Seamaster is known for its wonderful ability to show scuff marks no matter how careful you are with it. There are many ways that people have found to take the marks off. Some people use a polishing cloth, while others use other items such as a steel wool scrubbing pad. It depends upon what you feel most comfortable with, and what you find works best.

Insurance Issues:

Will an insurance company insure a watch with missing serial numbers and/or with out manufacture's warranty card?

Most insurance companies couldn't care less about serial numbers. You can insure a vintage Omega with no serial numbers, so why not a new one with no serial numbers? Again, most vintage watches have no warranty card and are fully insurable.

How can I let my insurance company know how much my vintage watch, or my watch with out a serial number is worth?

If they ask, an appraisal from a qualified person, or a receipt will usually be sufficient.

Bracelet/Band/Strap Issues:

Where can I get an Omega band for my vintage Omega?

Call the phone number below if you're in the United States. If you're not, look on the
Omega web site at, and look for the service center location nearest you.

I have a choice of getting the Omega I want on either a Strap or a Bracelet, which one should I buy?

Get the one you like, but keep in mind that you can always obtain a leather or rubber strap for much less than the metal strap purchased separately. Also, the metal band will outlast a rubber or a leather strap in the long run.

How do I remove links from my Seamaster, Speedmaster, De Ville, or Constellation?

You need the proper tools to do this. If you don't have them, then it's best to take your watch to an authorized dealer or a watchmaker. Omega makes a tough bracelet, and they also make a secure one. There are some tiny parts when taking apart the bracelet, and they are easy to lose/bend. You wouldn't want to ruin your beautiful watch by doing a do-it-yourself job on it, would you?

Where do I get straps/bracelets/parts for my Omega?

You can
contact Omega, or you can post a "wanted to buy" ad on the TimeZone sales corner at

Informational Number's/Sites:

What's the contact number/address/email for Omega service center in Pennsylvania?
SG Customer Service
1817 William Penn Way
Lancaster, PA 17601
Phone: 800 456 5354, Parts: ext. 3037 Repairs: ext. 3018
Fax: 717 399 2211
Are there other Authorized Omega Service Centers in the U.S.A.?
Yes, there are...
Factory Authorized Service Centers In the U.S.A.


SG Customer Service

1817 William Penn Way, Lancaster, PA 17601






Extension 3018



Extension 3037

Swiss Watch Repair Center

60 East 42nd Street, Suite 2328 New York NY 10165





Omega Service Agency

1010 Jefferson Bulg., 1015 Chestnut St. Philadelphia, PA 19107






United Authorized Service Center

Village Plaza, 1st Floor, 23400 Michigan Ave. Dearborn, MI 48124





SwissService Center

17 1/2 Calendar Court, La Grange, IL 60525





Omega Service Agency

4708 West 84th Street, Bloomington, MN 55437






Omega Service Agency

210 Post Street, Room 802, San Francisco, CA 94108





Walter Gooden, Inc.

2050 Bundy Drive, Suite 290, Los Angeles, CA 90025






Nesbit's Service

1425 2th Avenue, Suite 402, Seattle, WA 98101






Swiss Time Service Center

1101 S. Rogers Circle, Suite 8 Boca Raton, FL 33487





Time Tech

13140 Colt Road, Suite 519, Dallas Texas 75240





Does Omega have a web site?

Yes they do! Check it out at

Does Omega have an Official FAQ?

Yes they do! Check it out at
Omega FAQ. And for the questions they answer they're answers should be considered canon.

The serial number on my Omega is xx,xxx,xxx. Can anyone tell me when it was made?

Email Omega via their web page at, and click the "Contact Us" button, then send a message to the after sales department; they have all the records on your watch. Another way with detailed instructions is a short article written by one of the co-authors of this FAQ titled The how's and when's to contact Omega Vintage Information. While you are waiting for a detailed and exact answer from you can get an approximate production date within a couple of years by comparing it with the chart located in the article “Omega Serial Numbers by Year...

I wish to contact Omega in Switzerland, how do I know which department to send my email?

Follow this link to an article on the
The how's and when's to contact Omega in Switzerland. If you follow the directions there you will most likely sent your communication to the proper place...

Is there a time-line of Omega's achievements?

Yes there is. It is entitled
Omega, The Link Between The Past and the Future... It is most definitely worth checking out...

Other Common Questions:

I'm thinking about getting a winder for my automatic watch(es); can this damage them?

There are two schools of thought when it comes to this subject: Yes and No... Some watchmakers will tell you that using a winder will cause unnecessary wear to automatics, and wear parts down faster. A winder is intended to keep a watch that is used periodically wound, and not made to help preserve a watch.

The other option is to wind a watch by hand. In watches that can disconnect the winding train when winding by hand (you have to pull the crown out to wind the watch), there is minimal chance of damaging the watch. In watches that don't disconnect the winding train, wind these watches slowly, and only turn the crown 10-20 turns. Rapid and excessive winding will cause wear on the winding train since they don't disconnect.

Important Disclaimer:

The authors of this FAQ are not responsible for any erroneous information contained within this article. All views are the opinions of the authors, and should be used at the reader's discretion. If you have any questions, corrections, additions or suggestions for the authors please contact them (Damon) or (Chuck).

The authors wish to thank the people whos names appear previously in the FAQ for their contributions to this FAQ, Bill Hudson for his suggestion for links to other TimeZone Resources, and the TimeZone Community as a whole for their contributions to our knowledge on the subject..

Version/Time Stamp: 2003.