The Seamaster 300 was first released in 1957 as a part of Omega's trilogy of "Masters" professional tool watches ----- the Seamaster for divers, the anti-magnetic Railmaster for engineers and scientists, and the Speedmaster for race car drivers (that's right, it was never intended to go to the moon initially).
The Seamaster line of watches has been in existence since 1948, but those before the SM300 were really little more than dress type watches with limited water resistance ability. The SM300 was Omega's answer to the Blancpain Fifty Fathoms and the Rolex Submariner, released a few years prior. The "SM300" moniker was a bit misleading because it was only rated at 200 m water resistance, but Omega insisted that was due to the limitation of their testing equipment which had a maximum scale of 200 m. Omega was confident the watch could go all the way down to 300 m without problem.
All three "Masters" models initially shared the same broad arrow hands, non-screw down Naiad crown, and basic overall case design.
The first SM300 ref.CK2913 had a case diameter of 39 mm. Being 1957, some of the early ones probably had radium on the dial, hands, and bezel for luminescence. Due to serious health concerns, the use of radium on watches was finally banned in the late 1950s/early 1960s.
The broad arrow hour hand disappeared shortly after 1960 when the case ref.# was changed to CK14755, and then later to 165.014 in 1962.
The ref. CK2913, CK14755, and 165.014 were very similar watches with differences in the type of hands used, and minor dial and movement updates. They continued to use the same cases and bezels, and no date function was available. The three models also saw a transition from using radium to the new material (for that era), tritium.
On the CK14755, the broad arrow hour hand remained in use briefly, but the broad arrow was soon moved from the hour hand to the minute hand, and sometime later, the small arrow tip second hand appeared. The dials of the CK2913 and the CK14755 appeared to be identical.
The 165.014 brought a new set of hands. While the arrow tip second hand was carried over, the hour and minute hands became straight baton or "candlestick" shaped. The dial displayed a different font for the "Seamaster 300" script, as well as the numbers "3", "6", "9", and "12" at the quarter hour positions. Unlike the previous two reference models, the hour markers (which used to be triangular) were redesigned to rectangular shapes. The case remained at 39 mm, and still has the same straight lugs, used the same bezel design, and also the same crown.
The CK14755 and the 165.014 were transitional models between the early CK2913 and the upcoming ref.165024.
The next and final SM300 model was the ref.165024/166024, produced from 1962-69. The 166024 is the same as a 165024, with a quickset date function. It was said Omega had begun working on this new model as early as 1962, but the first watches were not available to authorized dealers until sometime in 1963 or even as late as 1964.
The no date version came out first, with baton hour/minute hands and arrow tip second hand, Naiad crown, and the dial carried over from the previous ref.165.014. The cal.552, 24 jewel automatic movement was also used in the CK14755 and the 165.014. The bezel and the case were redesigned. The 40 mm rotating bezel now has 60 minute divisions with 60 clicks. The case has been enlarged to 42 mm (in keeping with the Speedmaster), and the lug width was increased to 20 mm from the previous 19 mm. Gone were the straight lugs, they were redone in a twisted style like the Speedmaster's. The date feature was added no earlier than 1966, more likely in 1967 due to the fact that calibre 565 was being developed in 1966 and used in the ref.166024 version. Probably at around the same time, with the introduction of 166024, the famous "broad sword" (hour) hand replaced the baton hour hand that was being used on the 165024.
Beginning in 1966, the British Ministry of Defence (MOD) began negotiation with Omega regarding the specification for a diver's watch for the Royal Navy and military. The MOD's spec. and a drawing of the prototype of this watch looked almost eerily identical to the existing SM300 165024. The military specification included a "T" in circle on the dial, denoting tritium was being used for luminescence; a tritium filled inverted big triangle marker at 12 o'clock position, replacing the original number "12"; military serial #s engraved on the case back; spring bars permanently welded to the lugs; broad "sword" (hour) hands; a screw down crown for improved water resistance, and a 20 mm width NATO strap in "admiralty grey". The remaining specification was already fulfilled by the SM300 as is without the need for further modification.
Three of these military inspired features made their way into civilian watches, and soon became available to the public in or after 1967. The big triangle marker and the screw down crown were two such features, however, the broad sword hand seemed to be already in use before the MOD meeting.
Please note not all 1967 and later SM300s had the big triangle on the dial; Omega continued to make the version with the Arabic number "12" also, therefore the ones with the big triangle are especially desirable and such models are much sought after today by collectors.
The Phoenix Strap company was the original supplier of NATO straps for the British military, and it is still in business today. I bought a new admiralty grey strap from the company for around $17 pounds.
By the end of the 1960s, Omega no longer planned to continue producing the SM300, and the last watches were assembled and sold as 1970 models. The successor to the SM300 was the SM600 "Ploprof", another famous Omega and much sought after collector's item, but less aesthetic and practical as a regular daily wear wristwatch.
An interesting side note about military watches:
The British MOD had used a number of different watches for their military departments. After the early 1970s, the Royal Navy switched from using the SM300 to other brands including the Rolex Submariner. Those subsequent watches were modified to conform to military specification resembling the SM300. So a military Submariner (MilSub) is a Submariner with a SM300 style bezel and broad sword hands instead of the original Rolex hands, while a "MilSM300" is essentially the same watch as the regular civilian one. That's why a MilSub is especially pricey (if it's an original sample, fakes abound) because it is a marriage between a Submariner and a SM300 in very limited numbers not available for sale at any authorized dealer. Also, that's why a SM300 is such good value for money because you're getting a military spec. watch that's essentially the same as an actual military issued sample. Omega deserves to be complimented for that; the company seems to be very generous about giving the best of what it has to its customers without holding back anything.
Another side note: the MilSub came in two versions. The ref. 5513 came either with the original Rolex hands and bezel, or with the SM300 bezel and sword hands. The other, ref. 5517 came exclusively with the SM300 bezel and the sword hands. Needless to say, it's the SM300 featured version which is more valuable and harder to find. However, the MOD specification called for a 60 minute division bezel and sword hands, so how did the ones with the original Rolex parts ever came to be issued? Perhaps those were used by military of nations other than the British?
Some interesting things I've noticed about my SM300:
It is all original in unrestored condition, except for the hands. The hands are Omega replacement parts; you'll notice that the luminous material appears newer and has a slight greenish hue vs. the original tritium on the dial. That material is LumiNova, or Super-LumiNova, which is non-radioactive, and therefore does not degrade with time like radium or tritium. Tritium is radioactive, like radium, but a lot less. It is said the thickness of the watch crystal is sufficient to protect the wearer from most if not all of the radiation emitted. Radium-226 has a half life of ~1,600 years, whereas tritium's is 12.3 years; so my 48 year old watch hardly has much tritium left in it. The hands glow much brighter in the dark than the hour markers on the dial, as you can see in one of the attached pictures.
The calibre 565 movement is not chronometer certified, but contrary to my Constellation, has kept amazingly accurate time (+2 to +4 sec./day) when I received it. I believe this is due to a good servicing history. I took it to my watchmaker to have an overhaul anyway, and since then, it runs fast by more than 15 seconds/day. I will ask my watchmaker to readjust its rate when I take my Constellation in to be serviced this summer.
The date function is quickset (you can adjust the date by manipulating the crown). The date is advanced by pulling the crown out to the third position. The date moves forward by one day each time you pull and push on the crown; this is unusual compared to newer watches in which the date is adjusted by turning the crown.
The inside of the case back is stamped 165024 originally, but has been crossed out and restamped 166024. This worried me at first, thinking perhaps this case back maybe fake. I've searched and found pictures of other similar looking case backs on otherwise legitimate looking watches. My understanding is, Omega had decided to end production of the SM300 by the late 1960s, so in order to use up the remaining parts in stock, some of the surplus 165024 case backs have been restamped by Omega and used on those later SM300s with date function.
The date display is black numbers on a silver background. Another variation is white numbers on a black background. Both variations are authentic, but I find the black on silver not so easy to read, and the white on black blends in better with the "6" and "9" at the other quarter hour positions on the dial.
The watch came to me on a fine looking German made 22 mm black leather pilot strap, but I replaced it with a Phoenix NATO to better suit its military character.
The 165024/166024 is classified as a fourth generation SM300 by case reference numbers, but could also be regarded as second generation by case design (42 mm vs. the previous 39 mm versions) and overall appearance.
- Model ----- Omega Seamaster 300, diver's watch
- Purchased in October 2014 on Ebay from Sydney, Australia.
- Year of manufacture ----- 1968
- Case ref. number ----- 166024
- Movement serial number ----- 27 million
- Calibre 565, in-house non-chronometer movement, automatic winding, 24 jewels, 19,800 beats/hour, swan-neck timing regulator w/ adjustment screw, Incabloc shock protection system, copper-plated movement.
- Case diameter ----- 42 mm without the crown
- Case material ----- 316L stainless steel
- Width between lugs ----- 20 mm
- Type of bracelet ----- 20 mm admiralty grey nylon NATO strap by Phoenix Straps, UK.
- Power reserve ----- 50 hours
- Water resistance ----- 200 m
- Non-original "broad sword" hour hand, baton or "candlestick" minute hand, and white "arrow-tip" second hand; quick-set date function
- Original, unrestored matte black dial with tritium filled hour markers; inverted "big triangle" hour marker at 12 o'clock position.
- Domed triple layer Hesalite (acrylic) crystal with a tiny Omega logo engraved in the centre.
- Bi-directional rotating bezel with graduated 60 minute divisions and 60 clicks; black plastic resin bezel insert with sealed tritium filled markers
- Screw down type crown
- Stainless steel case back with hippocampus (seahorse) logo.
JTK a watch Guru from Canada.
HK Watch Fever