Deep Blue DayNight Scuba Review


When it comes to affordable boutique dive watches, one of the original names behind the rebirth of the trend is Deep Blue. Based out of NYC, Deep Blue was one of the earliest of the modern brands making overbuilt tool dive watches in Hong Kong (they also have Swiss-made watches), bringing both quality and good value with them. Their focus on using tritium gas tubes then set them apart from most of their competition, making their products unique and earning them cult status. In the years since the brands inception it has grown tremendously, now even having a booth at Basel, which is always fun to visit.


Despite having been around since before we started w&w, somehow we’ve never reviewed one. So, today we’re going to change that as we take a look at one of their core models, the DayNight Scuba. This 300m watch is a tool watch through and through, with a hearty steel case, great construction, some kickass lume, both tritium and SuperLuminova, and the various trappings you’d expect on a good diver. Coming in at $699, the DayNight has a sapphire crystal and is powered by the trustworthy Miyota 9015. So let’s take a closer look.

Deep Blue DayNight Scuba Review

Movement: Miyota 9015
Dial: Matte Black
Lume: T-100 Tritium tubes and C3
Lens: Sapphire
Strap: Steel
Water Res.: 300M
Dimensions: 45 x 52 mm
Thickness: 15 mm
Lug Width: 22 mm
Crown: 8 x 4mm
Warranty: Yes
Price: $699


Solid. That’s the single word that comes to ming when describing the case of the DayNight Scuba. It’s hefty, thick, dense and incredibly solid. Measuring 45 x 52 x 15mm, it’s a large watch, no doubt about it, but one with smart proportions, making it wear better than expected and perhaps look a bit smaller than it is. The design has a classic shape with thick, contouring lugs, slab sides and small but purposeful looking crown guards.  The majority of the case has light brushing for an even sheen, but running along the edge of the lugs and following the line of the case is a polished bevel. This detail does a lot to dress up the case, and since it’s perfectly executed adds an overall feeling of quality.


On top of the case is a well pronounced diver’s bezel. It features a 120-click uni-directional mechanism with a light, but precise snap. Speaking of solidity, bezels can be a point of weakness in any design, as they are a moving part with various tolerances at play. This one does not budge. It doesn’t take any special amount of pressure to rotate, but when it’s not in motion, there is no play. The bezel edge is designed with periodic deep cuts, rather than an edge texture, for grip. It works, and gives the watch a certain chunkiness I like.

Off of three is a screw down crown that measures 8 x 4mm. The wide but flat design makes the crown well proportioned to the case, but not stick out too much, saving your wrist from crown-bite. The crown has a simple design that mimics the bezel with occasional deep grooves, and a beveled edge. On the flat outside surface is Deep Blue’s clover-esque logo. Flipping the watch over, you have a solid steel case back with a light etching in the center of a diver beneath waves. Around the edge of the art are all the various details about the watch, including the 300m water resistance.



The dial of the DayNight Scuba is clean and bold, with a design that is largely defined by its use of flat tritium tubes. The main surface is matte black with an inner circle featuring a wave-form pattern. It’s a subtle texture that is only viewable in good lighting, and does a good job of activating what would have been empty space. Within this area is various text: Deep Blue logos below 12, and a block of small text above 6 reading “DayNight Scuba T-100”, “300 Meter/1000 Feet” and “Automatic” each on a separate line. It’s quite a bit of text though the small font keeps it from over taking the dial. That said, I wonder if it is all necessary info for the dial.


The primary index consists solely of large, rectangular, flat tritium tubes. Thought they might look like applied markers painted with lume, each is in fact a tube filled with radioactive tritium gas, which in turn lights up a layer of illuminating material for a constant glow. This is my first experience with a watch with flat tubes, and I like them. I like tritium in general, but these integrate more sensibly with a dial design. The tubes then are all green, save those at 12 which are orange. 12, 3, 6 and 9 are all presented with double tubes, giving the dial a slight cross-hair feel. In daylight, the tubes just appear a bold markers, simple but effective. In the dark, these things really light up. Once your eyes adjust a bit, the tubes are quite exceptional. Between each tube are white lines for the individual minutes/seconds.

At 4.5 is an angled date window showing a black on silver date, the Miyota 9015 standard. Given the block of text there, this feels a touch crowded. Use of a white on black disk might have opened this up a bit. Stepping out to the bezel, you have a classic diver’s insert with C3 superluminova filled markings. The first 20 minutes are each marked with a hash line getting larger at intervals of 5, ending in a sizable “20”. You then have numerals every 10 alternating with bold lines. The font used is big, blocky and bold. You can’t miss it. The origin marker is an oversized triangle, the point of which would extend into the dial, so it’s cut off. The lume here is also exceptional. With an initial charge, the C3 is way brighter than the tritium, though the tritium is a constant even glow and the C3 fades. One very cool detail is that there is a small orange tritium tube embedded within the origin marker, mimicking a lume “pearl”.


The DayNight Scuba features a very cool and seemingly unique handset. The hour and minute hands are both tapering sword shapes, not quite Roman sword style. Both are in white, and feature a small stem where they meet the central axis. Both feature long orange tritium tubes embedded within them along a center line. Here’s my favorite part, there is a black line running down their centers, giving the hands the sense that there are two white wings joining on the tritium tube. This simple detail makes them much more aggressive and interesting… bringing to mind Tie Fighers (but perhaps that’s just me). The second hand then has a more typical design, with the addition of an orange tritium tube towards its tip.


Straps and Wearability

The DayNight comes mounted to a heavy steel, oyster style bracelet. The 22mm end-links are solid, giving the case an almost barrel shape. The bracelet then tapers from 22 to 20mm for  more elegant lines, and likely adding a touch more comfort. The clasp is a standard flip-lock type with Deep Blue’s logos etched in (don’t mind the desk dive marks on the sample). Overall, it’s, once again, very solid feeling with only a touch of wiggle. Design-wise it works with the watch in a classic fashion.


On the wrist, the DayNight Scuba is a big watch, but wears smaller than I had expected. The 52mm lug-to-lug balances the 45mm diameter. So while certainly wide it didn’t feel too long on my 7″ wrist. The 15mm height is also tempered by the width, being spread out. Though I am a self-proclaimed small-medium sized watch guy, I do find the occasional appeal in a large watch if it is balanced (2 of my regular wears are 43mm, after all). Divers in particular tend to be the most tolerable because their bezels force the dial diameters to be smaller, so you don’t get that plate-on-the-wrist look. With this watch in particular, because of the size of the flat tubes, the dial couldn’t get smaller, nor would you want smaller tubes, so the size seems correct. It’s just not for every wrist.


Aesthetically, the DayNight is pure modern sport watch. It’s sleek and aggressive, but not flashy or ostentatious. In general, it lacks superfluous detailing so it comes across clean and mature. It’s bold, sheerly because of its size, but I think in general subdued enough to wear to the office. Naturally though, this watch wants to be in the water, and seems like it would work well for your average diving needs. Though I haven’t tried the tritium tubes under water, the idea is sound as to why you’d want them… I can tell you that in a movie theatre or dim bar, these things light up like a Christmas tree.


All in all, the Deep Blue DayNight Scuba is a good no-fuss tool dive watch for those looking for something with tritium and a large size. The build quality is very impressive all around, rivaling watches far more expensive. The polished bevel and sturdy bezel mechanism stand out in particular as highlights of the quality. The flat tritium tubes then really seal the deal. They look good in the light, and are something really special in the dark. At $699, the DayNight seems fairly priced for the quality you receive. Sure, there are Miyota 9015 powered divers for less, but also some for more, and for the reasons stated above, I think it’s a good value. So, if you’re in the market for a 45mm diver with the power of radioactive lume, be sure to check it out.

Images from this post:
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Zach is the Co-Founder and Executive Editor of Worn & Wound. Before diving headfirst into the world of watches, he spent his days as a product and graphic designer. Zach views watches as the perfect synergy of 2D and 3D design: the place where form, function, fashion and mechanical wonderment come together.
wornandwound zsw

14 responses to “Deep Blue DayNight Scuba Review”

  1. silkhead says:

    the sample seems a little beat up at the clasp

    • wornandwound says:

      yeah, this was a well worn sample, but sometimes it’s good to see what a watch will look like down the road a couple or years too.

      • Boogur T. Wang says:

        Is the sample, used for the pictures and review, for sale at a steep discount?

  2. Curmudgeon says:

    I’m pleased with this watch. And I’m nearly impossible to please.

  3. Jessé França says:

    This is actually a great watch, the tritium lits up like a lamp, it is impressive. Love to go to the movies and dark places with him, everyone take a peek. It is way brighter than a T25 watch (I used to have a traser). Will never downgrade off of tritium T100.

  4. Julius Swerving says:

    I think Deep Blue makes some nice looking watches, but I’m disappointed they don’t have any more modestly sized offerings. I bought their smallest watch and it was still too chunky.

  5. Emily Enderson says:

    Hey thanks for sharing
    this. Amazing collection of watches, perfect collection for all occasions. Also

  6. Li Wang says:

    There’s something funky and cool about their entire lineup. I don’t think I’d buy one for myself, but I’d love one as a gift.

  7. Boogur T. Wang says:

    Nice watch. I like it. I would wear it.
    But nothing really exceptional.

  8. Michael G. Curry says:

    I have the Similar Daynoight recon (65 tubes) basically regular tubes but on all the minute markers too and a ceramic bezel its a great watch very solid. Sits with next to my planet ocean in the watch box. (on a mesh in the pic has the same Bracelet as the scuba. Bought it directly from them in their NY location, message them on the forums and they would have you by.

  9. Steve says:

    Interesting, you covered its looks but didn’t touch on the movement.
    Is it all show and no go is that why you neglected the most inportant part of this watch?
    Poor review, perhaps there is another field of work where shallow exercise is more in line with your work.

  10. Superdad1 says:

    These are cheap watches which are NOT as water Resistant as they State. I own two of them and had them independently checked after a battery change and they both failed the depth test. My watch is rated to 1,000 feet but couldn’t pass a 100 foot test. Called manufacturer to get replacement gaskets and they didn’t have them in stock.

  11. arubatom says:

    I HAD their green dial face watch…I believe it was called the Ram or Sea Ram model…it had the date at an angle toward the bottom of the face, and it was really sharp looking. Anyway, when the battery went, I got a new battery, and when trying to get the old battery out, the plastic clasp that holds the battery in place broke. I sent it to a watch repair place for an estimate….I wasn’t the original watch owner, so I had no warranty info….I wasn’t sure how old it was. Anyway, they wanted $250 to repair it, as they said the movement also needed replacing….so maybe it wasn’t the battery after all???? Heck, I can buy a new one for around $350. Not sure if I will or not. Great looking watch and ran well, while it was working.