U-Boat Darkmoon Watch Review and Unboxing

With its deep, lustrous oil-filled dial, vibrant colours and mercurial love-it-or-hate-it compensation bubble, the U-Boat Italo Fontana Darkmoon watch offers an exciting and genuinely different timepiece.

• Mesmerizingly rich colour depth from the oil-filled dial
• Fashion-forward 44 mm unisex case diameter
• Easy-change ‘dry’ battery compartment

That playful air-bubble and deep, rich oil-filled dial make this timepiece instantly memorable and mesmerizingly engaging. We hope you enjoy our intro to a breathtaking on-wrist experience.

Read on, and then enjoy Jack Biggs’ popular U-Boat Darkmoon unboxing video on YouTube to understand why. Or if you just can’t wait to treat yourself or someone special, choose yours now.

You may see references to the ‘U-Boat Dark Moon Watch’ or ‘U Boat Dark Moon’; it’s easily done. However, according to U-Boat, Darkmoon is one word. This is the U-Boat Italo Fontana Darkmoon and, once seen, it’s unforgettable. Why dark moon? Because, to quote the manufacturer, it’s ‘A collection coming from the moon directly from its darker side’.

With this desirable range of handcrafted watches – proudly ‘Made in Tuscany’ – Italo Fontana has staked his claim for a slice of lunar-related watchmaking. We think they’re onto a winner. So does Paul Buchanan, whose encounter with an early Darkmoon led him to become the Italian watchmaker's UK sales manager.

A domed red glass that was stunning and mesmerising

Paul takes up the story: ‘Just over two years ago I met Richard, the U-Boat’s distributor in the UK and Ireland. He knew I’d grown disillusioned with the watch trade as brands just copied each other time and time again. He also knew I was seeking an inspirational brand. After teasing and tantalising me with U-Boat’s beautiful Chimera, he followed up with this watch with a domed red glass that was stunning and mesmerising in every way possible. While Richard talked I just sat there with the watch on my wrist and looked at it from every angle. I bought that watch, one of the original Darkmoons, then became the brand’s UK sales manager. Two watches is all it took and the U-Boat Darkmoon red 44mm IPB is still my go-to watch of choice.’

Depth of colour

The rich colour of this oil-filled beauty was just one of the features that mesmerised Paul and drew him to the brand. As soon as you see these amazing watches you notice how a Darkmoon’s striking dial delivers a 'wide eyed', spellbindingly-three-dimensional depth of colour and heightened legibility. From first glance, it’s obvious that they’re very different to the information-heavy visual complexity of other U-Boat classics such as the U-Boat U-65 skeleton watch.

Since the first Darkmoon, adoption of sapphire crystal and dial colour intensity refinements for better readability make a great product even more impressive. And then there’s the signature compensating bubble moving around the dial in its crystal clear oil bath. It helps amplify the view of the two hands – there’s no sweep-second hand – which appear to float free above the dial.

A surprisingly amplified view of the hands

TikTok watch influencer Jack Biggs enthuses about these features in our U-Boat Dark Moon unboxing video. He says: ‘an additional benefit to the oil bath is that it magnifies the vision of the hands and compensates for temperature between zero to 60 degrees. I feel as though this gives it a more three-dimensional look to the watch and it gives it that deep feel on the dial.’

U-Boat themselves say the oil-filling gives ‘a surprisingly amplified view of the hands, which seem to float free as in absence of the glass’. It’s all possible through the proprietary oil bath technology pioneered in the Capsoil watch that premiered on Instagram in November 2018.

Since then, U-Boat has clearly worked hard on their second oil-filled product range. The result, Darkmoon, is now in its second iteration. It sits irresistibly alongside the original Capsoil Chronograph to dominate Watch Pilot’s U-Boat Italo Fontana product page where you can browse and buy the U-Boat watch of your choice.

At the time of writing, as Jack Biggs explains, the range revolves around Black, Cardinal Red, Elegant Brown, Noble Green and Imperial Blue Darkmoon watches. Naturally, they’re all equipped with the company’s signature left-handed ‘destro’ screw-down winding crown. And 50 m (5 ATM) water resistance, which is enough to handle splashes, gentle swimming and cold showers.

Depending on the model, strap and bracelet options include stylish light mesh, laser-cut handmade, hand-finished calf leather, and a vulcanised rubber strap embossed on both sides with the U-BOAT logotype in deep relief.

Case sizes and finishes

U-Boat’s watches are renowned for imposing case diameters – no-one goes unnoticed when wearing one! Though smaller than watches such as the 47mm U-47 Classico, 50mm Flight deck pilot’s watch or massive 55mm-diameter U-1001, the latest Darkmoon's 44mm case guarantees attention grabbing wrist presence.

Such distinctive dial design deserves a durable, visually contrasting case finish. Depending on the watch, look forward to AISI 316L stainless steel with or without an IP Bronze (e.g. the 8467/B Men's Brown Darkmoon) or IP Black coating (e.g. the 8464/MT Men's Black Darkmoon).

Unsurprisingly, U-Boat Italo Fontana make much of how the Darkmoon dial, hands and quartz movement are all immersed in a special proprietary oil bath. More about that later. First, here’s a word about the movement powering Darkmoon.

Visit the well-rated Calibre-corner website, or the website of Ronda AG and you’ll quickly discover that the Darkmoon’s 712.3 movement is a reassuringly tried and tested Swiss-made workhorse of the Swiss watch movement industry.

With the 712.3 inside your U-Boat watch, you’re in good company. It’s a proven two-handed 26mm-diameter quartz movement from a brand that also powers watches from names like TAG-Heuer, Raymond Weil and Yema. As the company explains, ‘Ronda produces mechanical and quartz watch movements with Swiss precision for numerous leading watch brands. Our products can be found inside brand name watches ranging from elegant and sporty timepieces to stylish fashion accessories to luxurious models.’

Since watchmaking’s quartz revolution in the 1970s, the accuracy and reliability of these movements means a battery is needed.

At first glance, with Darkmoon’s dial and movement immersed in oil, changing the battery every few years would appear tricky. Because of the oil bath, early versions of the U-Boat Capsoil – this sounds like a portmanteau word derived from ‘encapsulated oil’ – needed specialist factory-attention back in Italy when the battery ran out. The same applied to early versions of the U-Boat Darkmoon watch.

Later Capsoil iterations and the latest Darkmoon get round this with a separate user-accessible battery chamber in the caseback. Kept oil-free by the innovative internal locking-ring system, it’s a welcome improvement over the first generation Darkmoon.

A clearly identified battery port

Look closely at Darkmoon’s caseback in Joe’s video and you’ll see the clearly identified battery port engraved with the battery identifier – SR936SW. This, and a different surface profile, differentiates the battery port from the (upper) oil regulation port. According to the manufacturer’s instruction manual, that one’s for use, ‘exclusively by U-BOAT specialized technicians’. In case you decide to explore, don’t say we didn’t warn you!

In his video, Jack raves about this important product improvement: ‘…previously on the traditional U Boat Dark Moon watches they only had one port. To change the battery you actually had to send it back to Italy, which could have been a massive inconvenience because it took about six to eight weeks to replace, which can be very annoying for those that are spending a lot of money on a watch and can’t wear it for a certain period of time.’

U-Boat attention to detail

Now, thankfully, having a dry battery port makes it easy to replace your U-Boat’s battery. In fact, it’s probably easier than removing the caseback and changing the battery on a conventional quartz watch. It’s just another example of the U-Boat detailing and continuous product refinement that we’ve come to expect from the Tuscan company.

Chances are you already know about U-Boat Watch Italo Fontana and how the Italian watchmaker has grown since 2000.

That was when Italo Fontana discovered grandfather Ilvo’s 1942 designs detailing an innovative watch for the Italian Navy, the Regia Marina.

For whatever reason, the design didn’t go into production. Instead, decades later, it inspired U-Boat’s founder to create his watch brand. Since then, Italo Fontana’s hand-crafted luxury watches, with their large cases, distinctive left-handed crowns, and signature retro-nautical – ‘Steampunk’ even, according to some commentators – designs, have built a loyal following.

Compared with many U-Boat designs, the Darkmoon may appear remarkably restrained. However, its striking sunburst – U-Boat call it soleil – dial, under that seductively curvaceous domed sapphire crystal, is anything but low-key.

Inspired by the dark side of the moon

Here’s what Rob Corder, editor of respected watch-industry magazine WatchPro, wrote in September 2020:

‘U-Boat has added to the Capsoil family this year with a sub-collection called Dark Moon [sic] — a reference to the blackness of their dials being like the dark side of the moon — and even given them a horror inflection with a blood red and black model. Mr Fontana channelling his inner werewolf, perhaps.’

It’s interesting, but not surprising, that the rich-red glow of the magnified dial on that particular model evoked such a visceral response. It was the same when we showed the range to Michael Langley, an experienced visual designer, founder of Uchi Clothing and creator of the Uchi Horology Series of watch art and clothing:

Visually arresting

‘When I look at a piece like the red-on-black U-Boat 8466/MT,’ he says, ‘I’m impressed by the striking, visually-bold design that’s both practical looking and visually arresting. The liquid filled domed crystal and huge dial numbers increase the submarine vibe. If any of the Darkmoon range suggests such a strong connection to U-Boat’s traditional retro-nautical style it’s surely this one.’

For anyone attempting to understand why certain watch designs work so well, Watches Tell More Than Time, written by industrial design guru Del Coates in 2003 is a useful reference. Dipping into this book was a no-brainer when planning to write about Darkmoon.

It reminds of the iconic Movado Museum watch

Gazing at the Darkmoon’s peripatetic compensating bubble reminds of Movado’s Nathan George Horwitt-designed Museum watch from 1947, with its single round ‘midday sun’ motif at 12 o’clock. To quote Coates:

‘The [Museum watch] earned its status, instead, on aesthetic grounds, by virtue of the seminal innovation of a numberless face…it has become one of the most memorable and emulated timepieces of all time’.

A design leader for others to follow?

The U-Boat Darkmoon may not be the most sophisticated oil-filled watch ever made, or the most expensive. But by incorporating that essential compensating bubble into such a visually deep and impressive ‘high value-contrast’ dial, it might position U-Boat as a design leader for others to try and copy in future.

And then, thinking of horological design leaders who’ve experimented with oil-filling, there’s Benoît Mintiens’ innovative Ressence brand...

We won’t be the first commentators to be reminded of Ressence’s breathtaking – and seriously expensive – timepieces by Capsoil and Darkmoon. Actually, though they famously use oil-filled technology, they differ from the U-Boat watch in a couple of important ways.

Firstly, there’s the technology. The U-Boat Darkmoon completely immerses its Ronda quartz movement and dial in oil. Compare that to the TYPE 3 and TYPE 5 Ressence. They combine an air-filled chamber for the mechanical movement with an oil-filled upper chamber that delivers their trademark ‘water drop’ image projection effect. A sophisticated micro-magnetic transmission connects the two chambers.

Buy your U-Boat Darkmoon for well under £1000

The other big difference is price. As Watch Pilot co-founder Tim Harrison explains: ‘A Ressence costs the same as a mid-size Audi, but you can buy U-Boat’s Darkmoon from us for well under £1000! You even get some Tuscan 'Vorsprung durch Technik' too – that's all'avanguardia della tecnica in Italian! It's an exciting prospect when you remember that you‘re buying into this rather arcane oil-filled horological technology. And the stunning visual impact it makes possible.’

A poor man’s Ressence?

Is the U-Boat Darkmoon a ‘poor man’s Ressence’? We’ll let you be the judge of that. What we will say is that oil-filled watches have actually been around for decades, albeit as a specialised and exclusive horological sub-set... There’s Ressence of course, as well as anti-mist, reflection-free underwater mission watches such as Sinn’s UX. The rest, including timepieces such as the French Beauchat Genesis 4000 HPS, or Hydroil-filled Bell & Ross Hydromax 11100M, complete an exclusive club. But none, not even used examples, can be had for anywhere near the price of U-Boat’s latest Darkmoon.

As mentioned earlier, the moving compensating bubble on the Darkmoon (and Capsoil’s) face is a constant reminder of the genuinely-iconic Movado Museum watch.

Why’s it there? The bubble, which evokes strongly polarised responses from watch-forum participants, isn’t just a designer’s idle aesthetic indulgence. Instead, though having the capacity to delight or torment for hours that bubble exists for an important technical reason. It provides compensation when the oil expands or contracts with changes in temperature within the manufacturer’s recommended operating range of 0 ° and +60 °C.

We can only speculate about how many Darkmoon wearers will be unable to resist trying to hold the bubble directly above their watch’s centre post.

Is this a unisex U-Boat watch? Though U-Boat offers watches – such as its 8474 Rainbow Ladies Mother of Pearl – specifically targeted at women, it’s no secret that its primary audience has traditionally been young and male.

However, current fashion-forward watch-wearing regularly sees larger men’s watches gracing female wrists. According to U-Boat’s UK importers, with a 44 mm case that wears smaller than its dimensions suggest, Darkmoon is definitely wowing both sexes.

One of the best U-Boat watches for women

Make no mistake; this is arguably one of the best U-Boat watches for women at the moment. After all, why should such a visually-engaging horological objet be reserved for the boys, particularly in a world where women happily rock men’s Rolexes and other luxury timepieces?

Clearly, brand chemistry that endears U-Boat to male celebs such as Sylvester Stallone and Nicholas Cage also works powerfully on their female counterparts such as Israeli model Bar Refaeli and actress Lindsay Lohan. How about you?

So that’s the U-Boat Darkmoon. Do you love watches with a strong retro-nautical story, unmissable visual impact, and that conversation-starting oil-filled technology? If so, this piece, with its fascinating design and engaging ‘Made in Tuscany’ story could be for you.

Enjoy Jack’s YouTube video and soak up his infectious enthusiasm for these breathtaking timepieces. Then browse our collection of U-Boat watches for men – and women – to discover the wonderful dark side of the Darkmoon collection for yourself – or as a gift for someone special.