Omega Planet Ocean vs. Rolex Sea Dweller
Rolex and Omega are probably two of the most often compared mid-range luxury watch brands today. Many consider both the Omega Planet Ocean and Rolex Sea Dweller as arguably the ultimate diver's tool watches available on the market today and heads and shoulders above the rest of the competition. Since I'm fortunate enough to own both, I thought it might be a worthwhile endeavor to do a comparison between the two.
A short disclaimer: I'd like to state that while I'm trying to be as objective as possible, it is inevitable that a certain amount of bias be present in this comparative review, which is inherent in the nature of this 'WIS' thing…
On with the show!...
CASE & CRYSTAL
As you can see from the case dimensions, both watches are fairly similar in size. Compared to the 45.5mm PO, I think the 42mm version makes for more of an "apples to apples" comparison with the SD.
At about 14.5mm thick, these two watches are significantly thicker than their closest brethren, the Omega Seamaster Professional and the Rolex Submariner, which are both rated to 300m water resistance. While it is highly unlikely that any of the users of the PO or SD will ever exceed the advertised limit of water resistance of 600m and 1,220m respectively, it's really nice to know that these watches have been over engineered to this level. It's really impressive though that the SD's advertised depth rating is double that of the PO, and yet maintains a similar case size and thickness.
In the picture above, you can get a good idea of the side profile of the lugs. The PO has the classic Omega twisted lug design with alternating polished and brushed design, and has just about no sharp edges. The SD's lugs are rather sharp in comparison and are polished on the sides and brushed on top.
It is also notable that Rolex uses 904L grade stainless steel in the manufacture of the case and bracelet of the SD. Among the properties of 904L grade stainless steel are increased resistance to corrosion and a price tag three times higher than normal grade 316L stainless steel. More often seen in industrial applications than on a wrist watch, use of the 904L grade steel has both been lauded as a great technical advancement and criticized as simply a reason to justify an increase in price.
It has been suggested that the use of this grade of steel can prevent pitting of the case and case back through many years of use and exposure to the elements and the acidic sweat of its users. One consideration for those who are allergic to nickel: 904L grade stainless steel contains roughly twice the amount of nickel compared to the 316L surgical grade steel found in the PO. It has also been interestingly noted by the author that the luster of 904L grade stainless steel appears 'whiter', apparently due to the increased presence of nickel in the metal.
In addition to the thicker case, the sapphire crystals installed on the watches are thicker as well to boost water resistance. This is more obvious on the SD, where the crystal noticeably raises up above the bezel. The downside of this is that the edges of sapphire crystal could possibly chip if knocked hard at the right angle, although this should not adversely affect the water resistance. I've seen this happen on some Sea Dwellers. In comparison, the crystal on the PO is almost flush with the case and well protected by the bezel.
While the sapphire crystals used on both watches are next to impossible to scratch, I feel that both models have their own shortfalls:
The Omega PO features a domed sapphire crystal which is coated on both sides with an anti-reflective (AR) layer. The benefits of these are firstly, that images that are reflected in the crystal appear smaller due to its slightly domed curvature, and secondly, reflected images appear in a bluish tone that enhances readability under harsh lighting conditions due to the presence of the AR coating. This AR coating, unlike the sapphire underneath, is prone to scratches and shows fingerprints annoyingly obvious, much to the chagrin of its owners. It does however give the watch a unique look, which admittedly may not be to everyone's liking. Fortunately, this layer of AR coating can be easily removed with a bit of polywatch and elbow grease should the need arise.
The Rolex SD has a flat, uncoated crystal. It gets the job done, but under certain lighting conditions, readability may be an issue. A domed, single coated layer of AR applied to the inside of the crystal would serve this watch well. During my time in the military, we were taught to take into account items in our possession that may potentially give away our position under cover. Given the Rolex Sub's and SD's history of being issued to various military organizations for use in the field, I'm somewhat disappointed that nothing has been done about the crystals on Rolex's range of sports watches. Any reflections off the flat crystal can be seen from a fair distance away. Not something you want when snipers are out and about!
At the heart of the Planet Ocean lies the Omega cal 2500c movement (left), which is based upon the ETA 2892-A2. Omega has modified the base movement to include the revolutionary Co-axial escapement designed by Dr George Daniels. This design is based on a double Co-Axial escape wheel, a lever with three pallet stones and impulse stone on the balance roller, together with a free sprung balance. This movement, in its current iteration, has been optimized to beat at an unusual rate of 25,200BPH or 7 beats per second.
The biggest upside of all this is a significant reduction in sliding friction compared with the traditional lever escapement, thus ensuring greater accuracy over increased service intervals. So far, my PO runs well within COSC specs and can be regulated to less than +/- 1 second over an extended period of time by playing with overnight positioning. However, the Co-axial escapement in its current form is still a relatively new design and has yet to withstand the test of time. It is yet to be seen at this point if Omega's claims on increased service intervals of up to 7-8 years hold true.
The Rolex Sea Dweller is driven by the legendary Rolex cal 3135 (right). Designed and manufactured 'in house' by Rolex, the cal 3135 has been in production since 1989 and has earned a reputation of being very reliable and robust. Several notable features have been implemented into the cal 3135, namely a Breguet overcoil balance-spring for better isochronisms, Microstella adjustment screws and a KIF shock absorption system. The movement beats at 28,800BPH or 8 beats per second. In layman terms, a higher beat rate would generally translate to a smoother 'sweep' of the second hand as it makes its way around the dial. The SD also runs well within COSC specs and gains less than 1 second over a 24hr period.
Perhaps the only downside of the cal 3135 is found in the winding rotor mechanism. Ball bearings are not used in the construction of the mechanism, and instead there is a plain sleeve bearing, in which proper lubrication is critical. Reliability may be compromised if this lubrication is insufficient or has dried/migrated.
The finishing on both movements is fairly utilitarian and probably won't be winning any beauty contests. However, this is what you'd expect of a tool watch, and most movements don't see the light of day until a service is in order. Not too big of an issue IMO.
Note: Other than the basics of movement design and implementation, the author is not very well versed in technical knowledge of the interior workings of these fine Swiss machines, and will therefore refrain from commenting on which is the superior movement. More information on the technical details included in this comparative can be found from various sources on the internet.
DIAL & HANDS
Readability on both watches is at an optimum, and I can think of very few other watches that can be read as quickly at a glance. (The W Speedy Pro comes to mind) Crystal reflections and the like not withstanding of course…
Both the PO and SD feature dials with applied minute markers. This really adds to the overall look of the watches, although some might say this detracts from the nature of a true tool watch. In this respect, I must admit that I much prefer the older matt dials that were found on the vintage Sea Dwellers and Submariners. The markers on the SD are a tad small and I would like to see the Maxi dials found on the LV subs implemented to the rest of the range one day.
The Omega uses a matt textured dial that does not reflect light. It is in fact black in color, but under bright lighting conditions, it appears as a slightly less attractive 'grayish' shade. The Rolex dial used in the modern SD is finished to a very high gloss, almost porcelain/enamel like finish. While this is attractive to many, it does have a down side in that 'ghostly reflections' of the dial markers can be seen in certain lighting conditions. The first time I saw these I thought it was the cause of a long day at work! Any dust or foreign particles trapped under the crystal also show up more obviously with the high gloss dial.
The design of the dial and markers found on the PO are a throw back to the original Seamaster 300m in the 1960s, which is a classic in its own right. I personally feel that the dial is better proportioned on the 42mm PO than the 45.5mm version. I prefer the shade of super-luminova that Rolex uses over the greenish tinge that is found on the PO. This might not be too obvious in the photos but it is very evident (IRL) in comparison that the PO's markers are fairly green. The applied W logo on the dial is an added bonus.
I remember many of the watches I owned growing up featured the famed Mercedes inspired hour hands. A true classic IMO, though some might say the look seems a little dated. I'm not the biggest fan of the broad arrow hands found on the PO, though they get the job done well, especially when it comes to the generous amounts of lume applied. The orange tip of the second hand on the PO adds a splash of color to the dial, but this orange may fade with time and exposure to sunlight to an unattractive bleached orangey-red.
The date wheel on the SD is black numbers on white background, whereas the PO has white numbers on black background. I much prefer the latter as this really rounds out the overall look and symmetry of the dial. The PO date aperture also features a beveled edge that gives it a nicely finished look. The SD date aperture in comparison looks like a hole was stamped into the dial. It's a shame that the beveled windows found on vintage SDs were discontinued after the days of the triple-six.
The bezel found on the SD is a true work of art. There is a certain heft in the precise 120 clicks that is sadly lacking on many other dive watches. The 'scalloped' edges of the bezel make for ease of turning and provide very good grip even with wet hands or gloves. The profile of the bezel is very robust, as you can see from pictures below, more so than the PO. The minute markers on the bezel are large and legible. One minor gripe though is the fact that the edges of the bezel are very sharp and could cause injury!
The PO bezel also provides a solid feel as it makes its 120 distinctly louder clicks around the dial. The coin edge is a real step up from the bezels found on the other SeMPs, which are next to impossible to turn with wet hands or gloves in the middle of open waters in the sea while fighting the strong currents. (Believe me I tried.) The level of finish is overall quite high with the alternating shiny and brushed edges of the coin. I do prefer the look and feel of the scalloped edge bezel found on the 45.5mm PO though, and continually hope that Omega will implement this one day on the 42mm. The minute markers are legible, if a bit small, and the silver ring on the inside of the bezel makes the watch seem smaller than it really is, not that these detract from the overall look of the PO. I've also found that the bezel on the PO can sometimes feel slightly 'tinny' (try tapping the bezel with your finger).
The biggest gripe here on both watches is definitely bezel alignment issues, most visible where the bezel pearl does not line up exactly with the dial. Though it's not entirely certain if this is due to QC issues or parallax errors due to the thicker sapphire crystals installed. As a saving grace, this can be relatively easily adjusted by any competent watch maker or even by yourself. (If you dare!)
Both models feature similarly large, oversized screw in crowns to allow for higher water resistance. Manually winding using the crown is buttery smooth and silent on both watches and you'd be hard pressed to do better.
The SD features the Rolex patented trip-lock crown, which feels really solid and has a nice spring action to it, went pulled or depressed when engaging the crown. The crown also features another gasket which is visible when the crown is pulled. Overall, it looks and feels very solid, and may be one of the contributing factors that put the SD's depth rating at double that of the PO's.
The PO crown is also a joy to use and easily engages with precise clicks. All gaskets and screw threads are elegantly hidden within the crown mechanism, though this might detract slightly from peace of mind!
HELIUM/GAS ESCAPE VALVE
As serious commercial diving watches, both the SD and PO feature helium gas escape valves (HEVs) for use under extending depth/time diving activities in which the use of a dive bell may be needed. These one way valves allow smaller helium molecules found in the air used in a diving bell, which can seep through watch seals, to escape from the watch during decompression after diving activities have ceased. A watch which has been saturated with helium may have its crystal, the most vulnerable part of its construction, forced out during decompression due to increased pressure within the watch when helium molecules are unable to escape quickly enough.
The SD features an automatic HEV that is flush with the case. This does look neater than the second crown found on the PO, and its presence is easily overlooked by SD owners. One consideration perhaps could be that the SD's valve could cease to function properly if clogged with dead skin cells, dust or sand. The HEV found on the PO comes in the form of a second crown located at 10 o'clock, which must be manually released upon decompression, failing which it will not function at all.
Given that the vast majority of POs and SDs sold will never see the inside of a dive bell, the presence of the HEV is moot. At best, the HEV is forgotten and would perhaps make an interested talking point during a party. At worse, the HEV could malfunction (in the case of the SD) or the crown could be accidentally engaged (with the PO) compromising water resistance and allowing water to flood the watch. Not good!
Screw in case backs are the norm for dive watches and these two are no exception. The SD has a fairly basic, utilitarian designed case back, which is engraved with ROLEX OYSTER ORIGINAL GAS ESCAPE VALVE. It also features the Rolex hologram that some collectors have been known to obsess over. Unfortunately, the smooth brushed case back underneath tends to allow the watch to slip and slide on the wrist when worn.
The PO case back is engraved with the W logo and the words SEAMSTER PLANET OCEAN, as well as a version of the Hippocampus or mythical sea monster of sorts. The PO case back is truly a work of art and has to be seen to be fully appreciated. Newer versions of the PO feature a laser engraved anti-counterfeit logo, which is a nice touch by Omega. The engravings, while a joy to behold, also serve the purpose of creating a certain amount of friction with the wrist, preventing the watch from sliding around too much.
Here are a couple of lume pictures. The PO is on the left while the SD on the right. Both watches were exposed to the same light source at the same time for the same amount of time before this picture was taken. Not surprisingly, the PO does glow brighter with its gratuitous amount of lume on the dial and hands. The SD is slightly disappointing in this regard to say the least. What is surprising is that the SD actually glows 'greener' than the PO.
A nice touch by Omega is how the hands and arrows nicely line up when the time is exactly 12am/pm. Illustrated in the shot below, you will notice that the 3 arrows do not cover each other when the hands are on top of each other.
The bracelet and clasp found on the PO is truly top notch. I appreciate the ease of maintenance with fully brushed exterior of the links, and the touch of class added with the polished sides of the links and fully solid stainless steel end, side and centre links. An added advantage is that the bracelet is of a 'non-self-marking' design. (i.e. the bracelet does not scratch itself when the watch is placed horizontal, dial up.)
The PO clasp is secure and comfortable and generally feels bombproof (if not scratch resistant!) That said though, proper sizing has proven to be an issue with many owners of the current Omega SeMP and PO range due to the lack of fine adjustment on the clasp. The bracelets are instead fine sized by adding half links. The full bracelet also happens to weigh a lot and makes for most of the difference in weight between the 2 models!
The Rolex bracelet on the other hand is well known for being criticized about feeling cheap and 'tinny' and not up to par on a watch of this price range. The bracelet has semi-solid end links and solid side links, but hollow centre links. It also tends to 'rattle' surprisingly loud when on the wrist or otherwise. However, it does do its job exceedingly well and is very secure without adding extra weight to an already heavy watch. Scratches also do not show as readily on the clasp, although the rest of the bracelet marks itself and the case back to hell. Rolex bracelets also utilize IMO superior screw links, which make for better security and easier self adjustment. (See picture below)
Both bracelets also support diver extension clasps for use when worn over a dive suit. Both extensions are of a fixed length and not adjustable. Rolex has however provided an extra extension link to lengthen the bracelet further should the need arise, which is a nice touch. I'd honestly rather strap on a rubber or NATO strap for diving purposes though. (Omega makes a nice OEM PO rubber strap)
While not the most important thing to consider when buying a watch, the package and goodies that come with it are a nice thing to have. Omegas come in the familiar white box packing and red vinyl box. To put it mildly, this box is poorly adapted to ageing. Even left in the safe, this thing will eventually start to fade and peel, and generally stains whatever it's in contact with a mild shade of red. Omega could really do better in this department and replace these boxes with the superior wooden lacquered boxes found with some limited edition speedmasters. The guarantee cards and accompanying wallet are nice though, and the instruction manual looks like it belongs on the coffee table. Ordering the COSC certificates is a nice bonus as well.
The Rolex packaging is nice and solid. Except that everything is a shade of green that I don't particularly care for. The plastic box supplied is impressively heavy. The warrantee cert might prove to be a problem if you have a flood. A nice touch by Rolex is the tool supplied for bracelet sizing, making for easier DIY sizing. The supplied plastic bezel protector likewise is a nice thing to have when storing the watch.
As you can see, I've left out any scoring system in this comparative review. I do believe that ultimately, the decision on which is the better watch has to be made for yourself. This review merely highlights some of the pros and cons that I have come to experience. Personally, the SD gets the nod for being a true classic in terms of design and implementation, whereas the PO perhaps can be considered as the next step in the continuing evolution of dive watch design.
I hope this fairly long comparative review has been of some use to those of you on the fence about these two watches. You really can't go wrong with either one though, and I'd encourage you to make a trip to your nearest AD that hopefully carries both brands. Try them both on and see which one speaks to you the loudest!
Thanks to Matthew J for pointing out that the Rolex box is in fact plastic…
Thanks to geremy for reminding me about the difference in dial finish and raising a great point!
Thanks to all the guys on the TZWF for the positive comments!