Citizen Promaster Eco-Drive Professional Diver 1000M Titanium BN7020-09E Solarzilla - The Ultimate Tool Watch, A Review (plus Video)

In my collection I have the 2002-introduced Promaster 1000m (Reference NH6931/NH6930) nicknamed the “Autozilla”. In 2017, when I heard that Citizen was pulling all the stops to come out with something spectacular for Baselworld 2107, I was curious to see the great reveal.

Citizen did not disappoint. The Citizen Promaster Eco-Drive Professional Diver 1000m (Reference BN7020-09E) is the world’s first solar-powered saturation capable diving watch. It is also Citizen’s second 1,000 meter diver. This watch is one of the few watches that can be define as an extreme dive watch. It is capable of exceptional depth and not suited for formal wear. It has been given the nickname “Solarzilla”.

The Solarzilla follows the design philosophy of its predecessor, the Autozilla. Slightly larger than the Autozilla, the Solarzilla is different in a few aspects. First, it is an Eco-Drive instead of automatic. Second, the new diver comes with an additional locking system that has a visual indication to show when the timing bezel is unlocked. Third, the addition of a power reserve reserve indicator.


I was actually contemplating not to get the watch due to the size. I saw some of the YouTube videos of owners with mix feelings about practicality of the Solarzilla as a daily watch. I was concerned that I would also not find it useful enough. Not only on YouTube but almost all watch bloggers find the size very daunting.



It is also important to note the wisdom behind the dive watch. The Solarzilla is all about doing one particular task and doing it well. If you plan to use it other than to dive deep, this watch is not for you. It cannot satisfy the needs of a sedated desk diver if it wants to perform for professional deep sea saturation divers as well. Here is where the concept of give-and-take or compromises does not work. You cannot compromise on a design that needs to perform in extreme conditions. Its like saying a ‘good’ F1 car must have a boot space for a pair of overnight bags!

I definitely fall under the desk diver category. However, I am also a watch collector and one of the ethos of my hobby is to collect watches with specific horological importance such as technology and concept. In this case, the Solarzilla fulfil that requirements under the following criteria: (1) the first Eco-Drive dive watch with 1000 meter water rating; (2) the first Eco-Drive watch with 1.5 years of power reserve; and (3) made using a special titanium alloy patented by Citizen with enhance strength. Based on this understanding, I quickly started searching with the hope of bagging one.



While walking in Bangsar Village 2 Shopping Mall, I came upon a watch shop called World of Watches II which happens to be a Citizen AD. Lucky me, there was one Solarzilla available. Based on Citizen’s website, the MSRP in Japan is YEN260,000 (excluding taxes) which is equivalent to RM9,578.27 (based on current FOREX rates). The official MSRP in Malaysian was RM9,820 (inclusive of taxes). After some persuasive bargaining, we settle to conclude the deal at RM7,100. Got a few free gifts as well.

The Case Material

To be able to sustain the immense pressure as per specification, the watch was made using some exotic materials. The casing is machined from SuperTitanium, a special material made predominantly from titanium and some other stuff under Citizen’s secret recipe. This special alloy is touted to be 5 times harder and 40% lighter than stainless steel. It has higher resistance to scratches in a wide range of colours with stronger hypoallergenic properties. Couple with its corrosion-resistant and anti-magnetic properties of titanium, the Solarzilla has one of the most well protected watch casing around. To make it even more capable, Citizen added a few more protective elements to the alloy in the form of the TIC process (titanium carbide), DLC coating (cold plasma vacuum adhesive process or otherwise commonly known as ‘diamond-like-carbon’ procedure) and the MRK hardening process (the addition of a hard amorphous carbon coating using mainly carbon and hydrogen to the titanium alloy). For more information, I have added the document from Citizen explaining the various proprietary methods used below.

Technologies on SuperTitanium on Scribd

In a nutshell: "Citizen’s Duratect MRK is a technology that maintains titanium’s original properties while hardening the surface of the material itself (as opposed to applying a coating to it). Two gases are injected into a special vacuum furnace and heat treatment applied to produce a hard layer about 20 to 30 microns thick on the surface of the titanium. Resistance to nicks is increased because the surface of the titanium material itself is made harder. Parts of the watch treated this way have their original blanc material colour.........Citizen’s Duratect DLC applies an amorphous carbon coating onto the surface of the titanium through. It’s a cold plasma technology and involves passing an electric current through hydrogen and carbon gases. DLC is an acronym for ‘diamond-like-carbon’. The DLC coating contains carbon and hydrogen (like a diamond) and lacks any grain boundaries. As a result, it’s extremely hard, smooth and scratch-resistant. The Duratect DLC technique has a higher level of adhesiveness than standard DLC technologies. The parts of the Citizen Promaster Professional Diver’s 1000M treated by this technique can be determined by their anthracite colour." - excerpts from the review done by FratelloWatches (https://www.fratellowatches.com/citizen-promaster-1000m/).

The watch is wide. Nevertheless, since the case is a perfect cylinder with no extruding lugs, it is a perfect 52.5 mm across. Equally impressive is the height that is 22 mm tall. Some may view this is excessive but it does help balance the width of the watch somewhat. In fact, this styling makes it easier to wear despite the size. It also has a large crown at 4 o’clock and an automatic HEV valve at 9 o’clock. As a diver, it comes standard with an external unidirectional bezel.

The Dial

The Solarzilla’s dial has a very simple layout. Deeply set inside the watch casing, the black dial is just one level. At the sides, the tall vertical chapter ring is polished which creates an impression that you are looking into a ‘hole’.



Looking closely, the dial surface is segregated into 3 circular zones. The furthest away is the thinest and it hosts minute markers painted in white. The middle zone hosts the applied hour markers as well as the date aperture. Finally, the centre zone hosts the power reserve indicator as well as some lines of text and a logo.

The applied hour markers are generously painted with Natulite luminous paint. Surrounded within rectangle polished frames, it shines extremely bright when charged with light energy. Only the 12 o’clock, 9 o’clock and 3 o’clock markers are different then the rest to compensate for being the primary point of reference, to accommodate the power reserve indicator and to integrate the date aperture, respectively.



The date window, located at 3 o’clock has a similar shape to the applied markers. Nevertheless, a sliver of the applied marker with Natulite paint is still located next to the date aperture to provide some illumination. As to maintain some form of balance to the dial, the Solarzilla uses black Arabic numerals on a white background for the date wheel. In daylight and from a far, the dial would look relatively symmetrical without gaps in the markers.

The power reserve indicator is located at 9 o’clock. It is fortunate that Citizen only needs to shave a bit of the 9 o’clock applied marker. The scale starts from “E” at the bottom and ends at the top (Citizen did not put the letter “F” or any other characters to balance the scale). Visually the scale shifts from a thin line which gradually expand at the end. Surprisingly, the scale is painted white from “E” and slowly transition to orange near the top. Colour-wise, it would be more meaningful the other way around.



As the anchor, the 12 o’clock applied hour marker is the widest of them all. It is easy to focus on it either in daylight of in the dark with the illumination working.

There are 6 lines of texts and logo on the centre zone and one line of text in extremely small font at the extreme South of the dial. The brand “CITIZEN” is located at the upper quadrant and in the centre. The technology reference “Eco-Drive” is located in the centre and offset to the right. In the lower quadrant the Promaster logo, “1000m”, “PROFESSIONAL” and “DIVER’S” can be found. Meanwhile, the text with the extremely small font reads “JAPAN J210-T034972 YI”. All of the texts and logo is painted white except for the “1000m” which is painted orange.

The hands on the Solarzilla are massive. The hours hand is shaped like an Apollo space capsule while the minutes hand is shaped like a flying rocket with two rocket plumes exiting the back. For the hours hand, the frame is polished steel while on the minutes hand, the frame is painted bright orange. Between the frames, a liberal amount of Natulite paint was added. Meanwhile, the seconds hand has a capsule silhouette in its middle painted with Natulite paint in the centre. Prior to this section, the seconds hand is painted black. Pass this point, the capsule silhouette has a bright orange frame which then extends all the way right up to the tip. I do have mix-feelings about the styling of the hands. To me it is a bit excessive as it does make it difficult to focus properly especially for the minutes hand. Nevertheless, it is unique and reflects the ‘extremeness’ of the Solarzilla. As I am not a diver, I cannot say for sure how effective the hands are when underwater. However, Citizen has made the necessary research and I am sure, the design does conform to the results of the studies.

The Casing 

Protecting the dial is a thick dome sapphire crystal with anti-reflective coating to minimise light distortions. Nevertheless, the highest point on the sapphire crystal is at least 1 mm below the bezel surface. This gives the crystal a lower chance of side impact damage as the bezel will take the brunt of it.



It is interesting to note that the Solarzilla’s dial footprint is only 29.5 mm wide when compared to the overall width of 52.5 mm of the watch. This mean that only 31.6% of the total surface area of the watch was allocated to the dial. The bulk was taken up by the large bezel mechanism unique to the Solarzilla. Looking like a six-tooth circular saw blade, the bezel comes equipped with an additional locking system that has a visual indication to show when the timing bezel is unlocked. This locking mechanism can be accessed on either side of the watch casing (at the top and bottom). Using the bright orange colour as an indication of danger, if visible, the 120-click ratcheting bezel can be rotated counterclockwise.



The bezel has two sets of scales. A minute scale consisting of small square minute markers on the inner edge. Next to it is another scale with Arabic numerals for every 5th minute except for the '0' or '60' minute marker which was replaced with a luminous pip. It would also appear that the bezel insert is attached to the bezel system by a set of four screws at 10 o’clock, 2 o’clock, 4 o’clock and 8 o’clock. The overall design of the bezel is handy and can be easily handled when wearing a thick divers’ glove.

I noted in many of the reviews about the watch, writers tend to comment about the ‘over-engineering’ done to the bezel. Some argue that the unidirectional aspects of the bezel is sufficient and the addition of the locking mechanism is an ‘overkill’. I believe these reviewers were judging and concluding with very limited information and knowledge. The Solarzilla is ISO 6425 compliant and has been tested for high-speed decompression with no problems whatsoever. Citizen also partnered with the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) to test the Solarzilla under live conditions. All the findings out of the field tests are surely adopted in the final product. I guess we need to have some trust that all the necessary empirical studies were conducted to justify the way the Solarzilla was designed.



The crown that controls the movement is located at 4 o’clock. A huge crown with an impressive dimension approximated 9 mm wide and 5 mm tall. With wide gear-tooth along the barrel of the crown and the Promaster logo etched on the top surface, the screw-down crown is easy to manipulate. The screw thread is easy to engage and it tightens down firmly. As a security measure, the stem of the crown is painted orange. If you can still see the orange, the screw-down process is not complete.



On the opposite side at 10 o’clock is the automatic HEV valve. When an excessive volume of helium gas accumulates inside the casing, the HEV valve will automatically pop open to vent it out. You will also able to see the words “PROFESSIONAL DIVER’S 1000m” etched on the side of the casing. These words are already inscribed on the dial and I just cannot see the justification of repeating it on the casing itself. Even if there is a good reason for the texts, how come there are no inscriptions on the opposite side as a counterbalance?



The watch casing is paired with customs black polyurethane straps with signed buckle. Instead of typical lugs that extends out of the casing, the Solarzilla uses an internal lug system. From the back you will be able to discern a ring that is attached to the casing by four screws. To replace the straps one must disengage this metal ring from the casing. Since the straps are clamped to the casing, it is more secure compared to linking them via spring-bars to lugs holes.



Due to the uniqueness of this attachment, it is extremely difficult to find a complementary strap from other makers. You would need to go back to Citizen for a replacement. This is a same situation with my Autozilla. Instead of trying to find a strap that fits into the special lugs, some manufacturers have produced lug adapters made out of titanium which would allow you to uses standard straps. I am not sure if the adapters for the Autozilla is compatible with the Solarzilla. If is is not, it will only be a matter of time before someone makes such adapters.



The strap has a number of features to help keep it secure on the wrist. I can find four features. Firstly, there is a “W” shaped kink on both sides of the strap to ensure some sort of spring tension be put on the wrist when strapped on. Secondly, the inner surface of the strap is undulating. This provide addition friction against skin or wet-suit. Thirdly, the first strap guard is fixed in place by a set of extrusions from the strap itself while the second strap guard is free to move. This ensures the loose end of the strap is not free to flap around. Fourthly, the end of the strap is thicker so as to make it difficult to simply slid out of the buckle.



Citizen also added in an extension strap than can be attached to the existing standard strap thereby extending the circumference of the strap.



Would it have been better to have a bracelet option for this watch? This is a question that I would ask. I suppose it can be done but I am sure some modification to the unique lug system be needed. If I had a say in the design specifications, I would suggest either a Jubilee style bracelet or a Milanese style bracelet for a good pairing.



The solid screw-down case-back has loads of information and a nice graphic on it. The embossed graphic of a diving helmet was beautifully executed. Underneath this case-back is the Citizen’s Eco-Drive movement, the J210 Caliber. Powered by light, the J210 movement can run for 1.5 years when fully charged. The J210 has six complications; power reserve indicator, date wheel, 3-hands, insufficient charge warning function; and overcharge preventive function.



The illumination on the dial is first class. It shines bright and last long through the night. Natulite is as good as Superluminova or Lumibrite.


The Wearing Experience

Trying to argue the merits of the watch in the context of daily wear is unfair. It was never designed for office or casual wear. Using the watch in these kinds of scenarios will only generate negative comments that mask its true nature.



For professional divers, this watch is an excellent backup dive watch. Why backup you must ask? Well, the dangerous nature of saturation diving requires real-time information and with new technologies, wrist computers are the first choice for such divers. Nevertheless, having a backup is essential and the Solarzilla is the ultimate standby if the primary unit fails. It is a good redundancy system as it does not have to be connected to an external power source ever so often, unlike dive computers. The 1.5 years of battery reserve is more than enough to be in the supporting role.



Despite the size, the use of titanium throughout the construction of the Solarzilla keeps the weight down to a manageable 180 grams. On the wrist, the watch feels light. Once you have all the diving gear on you, you would not even notice the weight of the watch.

The height of the watch does make it unwieldy. There is high likelihood of impact damage. Although the various level of protection added to the watch does blunt the potential surface damage somewhat, don’t expect the watch to remain unscathed if used as intended. Even so, the internals are well insulated and designed to shrug off most battle damage. Any damage would generally be localised at the surface level.




Specifications

Brand: Citizen
Model: Promaster Eco-Drive Professional Diver 1000M Titanium Solarzilla
Reference: BN7020-09E
Diameter: 52.5 mm
Dial Width: 29.5 mm
Lug Length: 52.5 mm
Lug Width: 28 mm
Height: 22 mm
Crown: Signed screw-down 9 mm wide, 5 mm tall
Case Material: Super Titanium™ (Duratect DLC+MRK+TIC)
Crystal: Domed sapphire (with anti-reflective coating)
Dial Color: Black
Indexes: Applied markers
Luminous: Natulite paint
Water Resistance: 1,000m (for saturation diving)
Band: Black polyurethane strap with signed buckle
Weight: 180 grams  

Caliber: J210

Technology: Eco-Drive, solar powered
Functions: Hours, minutes, seconds, date, power-reserve indicator

Power Reserve: 1.5-year power-reserve when fully charged
Accuracy: +/-15 seconds per month when operating between +5°C (41°F) and +35°C (95°F)
Operating Range: ‒10°C (14°F) to +60°C (140°F)

Additional Details:
- Automatic HEV
- Uni-directional bezel
- Bezel lock mechanism
- Insufficient charge warning function: two-second interval movement; ~ 4 days
- Overcharge prevention function

MSRP Japan: YEN260,000 (excluding taxes)
MSRP Malaysia: RM9,820.00
Availability: 2017
Warranty: 3 years

Solarzilla Manual by on Scribd

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