Spinnaker Dumas Review – 70’s Inspired 300m Diver

spinnaker dumas dial

Spinnaker is a highly specialized brand. They make watches for specific uses – most often for yachting purposes – but all of their watches are connected to the sea in some way. This particular model we are reviewing, the Spinnaker Dumas SP-5081-99, is designed with diving in mind.

The Spinnaker Dumas is named after Frédéric Dumas, a legendary underwater researcher and pioneer that is credited as one of the inventors of the scuba regulator that is used by modern divers today. Let’s see if the Spinnaker Dumas lives up to the man it is named after.


The Dumas has a fantastic bold, layered aesthetic that appears to be inspired by the Omega Seamaster SHOM, with some touches from the Seamaster Ploprof. This watch has a rugged design that will be sure to last a long time. Let’s take a closer look at these details. Our review focuses primarily on the SP-5081-99 model.

The Case

spinnaker dumas thickness

With a 316L stainless steel case and an octagonal shape with flat sidewalls, the Spinnaker Dumas has an angular and muscular theme. These walls have a chamfered corner in places where they meet the top surface of the case. With the exception of this chamfered edge, the case has a brushed finish on all sides.

One unique element is that the lugs are hidden from view to maintain the octagonal silhouette as much as possible. The angular crown guards and crown itself are the only places where this watch deviates from the octagonal shape.

The Spinnaker Dumas has dimensions of 43mm across, 48mm lug-to-lug, 16mm thick (bezel included), and a lug width of 22mm. As you can tell, the Dumas is a hefty watch and that’s because it is designed to stand out and make a statement. The case’s octagonal shape contributes to this with its retro and block-y look.

Behind, the Spinnaker Dumas is secured with a screw-down steel caseback with an exhibition window. The window provides a clear view of the complex engineering of the Spinnaker rotor and automatic movement that rotates away inside.

The Dial

spinnaker dumas dial

What makes this watch really stand out is its dial. Beginning with a grey base, markers are then applied on a secondary ring along the outer edge of the bezel. This ring creates multiple layers of depth with the hour markers and date window rising up above the rest of the ring.

The hour markers are mostly composed of large white circles with a grey outline that are filled with lume. For the 6, 9, and 12-o’clock positions, the shape changes to a rectangle with a double rectangle for the 12-o’clock marker. This helps differentiate the cardinal directions and helps you orient the watch

Printed on the dial base just inside each hour marker are Arabic numbers from 13 to 24 printed in navy text in reference to military time. Each minute/second marker is printed on the outer ring as thin navy lines, and thick red squares mark every 5 minutes/seconds.

There is no marker at the 3-o’clock position; instead, the date window is located there. Following the same design style, it is black text on a white background and framed with a raised navy trim on the applied marker ring.

Other pieces of text printed on the dial are the Spinnaker logo below the 12-o’clock marker, “AUTOMATIC” above the 6-o’clock marker in bright red, and “1000FT/300M” to signify its impressive water resistance rating.

How does Spinnaker manage to add so much depth and personality to this dial when it appears to just be a minimal grey dial? The answer is that they have many nice touches which elevate the overall look and feel of it. We already mentioned that it has an applied ring on the outer edge which the markers are printed on.

Additionally, the dial is recessed below the bezel and the hands are elevated above both the dial and applied marker ring. All of these levels of depths make a  world of difference in adding a dynamic edge to what would have been an otherwise boring grey dial. The dial is able to create a different feel from every angle, and when light shines on it, the shadows magnify this effect and produce a breathtaking view.

Depending on which model you get, the Spinnaker Dumas has different color schemes. From black, white, and orange, to blue, white, and orange, to yellow, white, red, and black, these color schemes are reflected on the dial and enhanced by the hands.

The Hands

spinnaker dumas date window

The Dumas’ hands are a true standout feature, and not just because they literally stand above the rest. The minute hand is the first thing that will catch your eye. It is shaped like a massive white, lumed sword that has a bright trim to really make it stand out.

Unlike the bold minute hand, the hour and second hands are more reserved and consist of white lume with a grey trim. The hour hand is a stubby pencil shape, and the second hand is a thin, tapered navy stick with a lume circle on the pointer side. As mentioned, these hands will match the color scheme of the dial.

The Crystal

spinnaker dumas crystal

A scratch-resistant, anti-reflective sapphire crystal keeps the dial safe from the rigors of diving and daily wear. The flat crystal sits level with the bezel edge. It provides a clear view to the dial without any distortions even when viewed at extreme angles.

The Bezel

spinnaker dumas bezel

Next, the bezel has a mineral crystal insert with lume markings and a glossy finish. Its color will depend on which version you get. The edge is made of polished stainless steel and it has grooves which provide extra grip when rotating it.

At the 12-o’clock position, the marker is triangular with a luminous pip to help with orientation in the dark. Embossed rectangles make up the markings on the bezel, and this design often reflects lines of light. Thicker rectangles mark each 5 minute interval, and smaller markers mark each minute up to the first 15 minutes.

The Crown

spinnaker dumas screw-down crown

Spinnaker is not the type to disappoint with its crowns either. The Dumas’ crown has a width of 5.5mm and 7.0mm diameter. While this may seem a bit on the larger side, we feel its proportions are perfectly suited to the sizing of the case. This crown features a polished gripping surface with cut grooves; an aesthetic that matches the bezel’s grip edge.

The flat side of the crown has a design that we have never seen before – a white mineral crystal insert with the Spinnaker sail emblem can be found inside. This is a unique and well-executed touch that makes the Dumas stand out as high-quality.

The Band

spinnaker dumas bracelet

Another touch that demonstrates the Seamaster SHOM’s influence on the Dumas is the inclusion of a stainless steel sharkmesh band. This band has a width of 22mm which is a perfect size for this case. With that said, the band is incredibly thick. It measures 4.0mm thick and gives off a bold and muscular image, particularly with the included machined steel hardware.

The included clasp is a durable fold-over deployant style with a brushed finish as well as an engraved Spinnaker logo. A blocky stainless steel loop-catch is included to hold onto the excess strap on the open end. This design projects an image for strength, but perhaps it may look too bold for some people, especially considering the band can add 8mm of thickness over areas where it overlaps itself.

However, band problems are easy to fix by replacing it with an alternate strap. It wouldn’t be a bad idea to add a NATO strap to the Dumas. In fact, they look right at home, almost as if Spinnaker watches were designed with NATO straps in mind. Since the lugs in the Dumas are “hidden”, removing the spring bars can be a bit of a challenge. Furthermore, the case doesn’t give a lot of leeway so not all straps will easily fit.

Even if you are planning on replacing the default strap with a thin nylon one, for example, the spring bars must be removed from a tight space so even swapping to a less bulky strap can be arduous. In our opinion though, it is worth it for not just the style, but comfort as well. We will expand on what we mean in the “Usability” section below.

Overall Style

The Spinnaker Dumas is a large, retro-style octagonal-shaped watch. However, it adds its own modern touches to keep up with the times and to make it look unique and interesting. It has numerous color options offered so you can find the one that best fits your style.

Everything about this watch screams macho and bold, but it is a dive watch and a tool first and foremost. The angular style of the octagonal profile is reminiscent of the design of watches from the 70s. We are fans of retro-style watches that look like a blast from the past; it gives off the same retro-chic vibes as the Seiko Turtle.

With that said, this specific look means it looks best in casual settings. It’s best worn with a diving suit or a T-shirt and would look awkward and out of place if worn with a suit in a formal setting. However, rules are meant to be broken, and you certainly could wear it to make a bold statement and add some edge to the occasion.

The Movement

spinnaker dumas movement

We’ve talked a lot about the Spinnaker Dumas’ appearance, so now let’s take a look inside. What exactly is keeping this watch ticking? As we mentioned, there is a glass exhibition window on the screw-down caseback which gives wearers a peak of the complicated internals. What you’ll find is the Seiko NH35 automatic movement moving rapidly inside. This particular movement is commonly found in microbrand watches due to how cost-effective they are.

Furthermore, this movement is essentially an unbranded version of the Seiko 4R35, a movement that is used in many watches in Seiko’s Prospex line. Here’s what the movement offers:

  • 21,600 beats per hour (6 beats per second).
  • 41-hour power reserve when fully charged.
  • Regulation possible.
  • Handwinding.
  • Hacking.
  • 24 jewels.
  • Date complication.

The Seiko NH35 is relatively accurate, with a range of +/- 15 seconds a day. However, if you are not satisfied with how accurate your watch is, you can easily adjust the time even down to the second. The date will adjust on its own every night at around 10:20pm and will change over at 12:00am sharp.


The Spinnaker Dumas was built with usability in mind.

Water Resistance

spinnaker dumas hands

We aren’t surprised by how heavy-duty this watch looks as the Spinnaker Dumas has a water resistance rating of 300m or 100ft. This is equivalent to the Rolex Submariner’s depth rating, which is a legendary dive watch several orders of magnitude more expensive. That’s impressive.

With that said, we searched and couldn’t find anywhere that states that the Spinnaker Dumas is ISO 6425 certified. Having this certification would mean that it means certain stringent safety standards and that it qualifies as a legitimate professional dive watch. Despite not being certified, the Spinnaker Dumas’s specifications seems to already meet some of these requirements.

For example, in addition to the impressive water resistance, the Dumas also has clear, distinguishable markings on the watch dial, sufficient lume on its markers, hands, and bezel, a unidirectional rotating bezel with markers every 5 minutes or less, the ability to tell the watch is still functioning in the dark, and the ability to operate the watch in complete darkness at a minimum distance of 25cm.

Some requirements that we aren’t sure the Spinnaker Dumas meets are its magnetic resistance, shock resistance, saltwater resistance, and strap/band strength. You can find the exact requirements needed to pass the ISO 6425 certification here.

Even without being officially ISO 6425 certified, we are confident that the Spinnaker Dumas can hold its own against rough water conditions. Thanks to its robust design, the Spinnaker Dumas can be used for swimming, snorkeling and recreational diving.

Operating the Crown

One of the reasons for the Spinnaker Dumas’ impressive 300m water resistance rating is thanks to the screw-down crown. The crown can be screwed down to form a watertight seal to prevent any moisture from entering.

Crown guards stick out from the case to protect the crown from being accidentally turned due to being brushed against or hit by something. This reduces the likelihood of the seal being broken and water flooding in. The crown is quite large, but in proportion to the size of the case.

Here are the various positions the crown can be set to:

  • Full in: While unscrewed, you can rotate the crown clockwise to wind the mainspring. The NH35 movement has excellent audible and tactile feedback in response to the manual winding.
  • First click (middle position):  When pulled halfway out, you can rotate the crown to adjust the date window.
  • Second click (full out): When pulled all the way out, rotate the crown to adjust the time. Since the movement allows hacking, all hand movement including the second hand will cease, allowing you to accurately set the exact time.

Once you are done adjusting the crown,  you can screw it down to form a watertight seal. We highly recommend you only rotate the crown when the watch is off your wrist. It can be hard to fiddle with it using only one hand, and you may end up damaging the crown if you are not careful. During daily wear, the crown guards should offer enough protection to guard against most impacts with desks or doorways.


spinnaker dumas markers

The Spinnaker Dumas’ legibility is very high and telling the time can be done quickly thanks to the excellent contrast between the hands, markers, and dial. The many layers of depth that the dial has as described in the “Dial” section helps certain components literally stand out. Furthermore, the hands are sized differently so you can easily tell the hour from the minute hand and so on.

For a dive watch, the minute hand is perhaps the most important metric in being able to quickly tell how much time has elapsed and how much remains. Therefore, it was wise of Spinnaker to make such a large, differently colored minute hand so that it stands out from the rest.

Based on the hands’ design, even the time can be read with just a mere glance. The clarity of the sapphire crystal, with the support of the anti-reflective coating, means the Dumas will not catch any glares nor will it distort the view even when viewed at an angle. Furthermore, the sapphire crystal will also ensure that the dial is protected from any impacts. Sapphire is the most durable glass option that a dive watch can have, and it is also scratch-resistant.

In addition, the dial and bezel markers let you tell time down to the exact minute. Each hand extends all the way out to the marker so that there is no question as to which marker the hand is pointing to.

Lastly, the date window at the 3-o’clock position is helpful for those who want a reminder as to the date. There is no day option. The high contrast between the grey background, black font, and bold trim helps it to stand out and makes reading the date very straightforward.

Using the Bezel

The markers on the bezel improve the overall readability of the watch as well. With its special triangle marker at the 12-o’clock position, it is easy to track the orientation of the bezel. Smaller markers march each minute up to the first 15 minutes so that as your time runs low, you can more precisely track how much time remains.

Furthermore, the rectangular markers at the 3, 6, and 9-o’clock positions act as reference points as well, and the smaller tick marks for every 5 minutes further increases the speed at which you can read the time.

Rotating the bezel on the Spinnaker Dumas helps you track not only elapsed time, but it can also be used to track the time in a second time zone – a helpful feature.


spinnaker dumas lume

Using the Spinnaker Dumas at night or in the dark while deep underwater is possible thanks to the Swiss Super-Luminova applied to each marker on the dial and bezel. The lume is super indeed with how bright and crisp it is. It lights up in a bluish-green hue and lasts for hours.

It should not be an issue using this watch in the dark, particularly because the huge sword-shaped minute hand is so clearly visible at all times. In fact, the glow from the minute hand is so strong that it practically appears to be backlit, illuminating a portion of the dial behind it.

With that said, the extreme brightness provided by the lume lasts only for the first 15 minutes or so, then will gradually decrease to a low-level state where it will remain for a long time. This process is the same for all lume, but lower-quality lume will be even dimmer and lose its glow faster.

Even as the Super-Luminova dims, it is bright enough that you can read the time in the dark easily. The charge lasts for over 8 hours in the low-level state, which is more than adequate for a day of diving.

The Bracelet

spinnaker dumas lugs

The Dumas’ sharkmesh strap with deployant clasp offers a decent amount of adjustability for sizing it to your wrist and this can be done without any tools. The clasp is straightforward to open and close, and when closed it feels snug and secure on your wrist.

One issue we had with this bracelet was with how it handles the excess strap portion. While the Dumas does include a metal strap loop intended to secure this excess portion, the loop is not secure enough and tends to slide down during regular wear, letting the excess strap hang off the wrist

Additionally, when putting the watch on, it can be hard to get the loop to slide over the excess portion. You may need to slide and finagle your way through, and when it comes loose, you have to repeat this process which can be annoying.

The bracelet is connected to the lugs with a spring bar. The lugs do not have drilled holes, so you need to access them from inside which is straightforward enough to do.

We highly recommend you swap out the included bracelet with a NATO strap instead.


With such a bold and macho watch design, it shouldn’t be a surprise that comfort is going to be affected. As we mentioned above, the Spinnaker Dumas has an octagonal profile and is very thick. Not only is its case 15mm thick, but you have to consider that the bracelet is 4mm thick and where it overlaps, it adds an extra 8mm of thickness. This also affects how heavy the Dumas is, which is a hefty 7.2oz/204g. However, much of this can be fixed by simply replacing the bracelet.

The bracelet contributes nearly half of the watch’s total weight. Plus we have already mentioned its annoying usability issue. That’s two strikes and since this isn’t baseball, the bracelet is out. The first thing you should do when you get the Spinnaker Dumas is replace the strap with a NATO strap.

Replacing the strap not only significantly lightens the watch, but now you don’t have to deal with the metal edges of the sharkmesh that can irritate the skin. This improves the watch drastically from a comfort perspective. It will feel like a world of a difference once the NATO strap is on. After the swap, the case size and weight will barely be noticeable and the Dumas will be as comfortable to wear as other high-quality watches.

With that said, replacing the bracelet doesn’t change the fact that the case itself is 15mm thick. Removing some of the thickness makes it easier to slide under the cuff, however it may still occasionally snag on the cuff based on its inherent thickness. As such, the Dumas is best-suited for casual environments where you don’t need to dress up.

Additionally, based on its large size (44mm diameter, 48mm lug-to-lug), people with smaller wrists may have some difficulty wearing the Dumas. With that said, perhaps you can make it work and the large size of the Dumas can help you make a statement. However, the Dumas fits average-sized wrists the best.

The crown is a decent size and may occasionally contact the skin. Since its flat side has a rounded surface with a mineral crystal insert, it should not feel too irritating when it does press against the skin.

Overall, comfort is a major issue with the included bracelet. This is something that can be mostly mitigated by replacing the bracelet.

Spinnaker Dumas Review: The Verdict

Clearly, the Spinnaker Dumas is a dive watch that is designed with usability in mind. It provides many features such as an impressive water resistance rating of 300m/1000ft, excellent readability due to the design of the dial and its strong lume, a high-quality sapphire crystal with AR coating for clarity and durability, Japanese automatic movement with hacking and handwinding, and a 24-month warranty.

There’s lots to like about the Dumas, but it isn’t perfect either. The included sharkmesh bracelet is not comfortable and causes the usability to take a hit. At the time of reviewing, the Spinnaker Dumas costs $400, and this is a fair price for what it offers even if you factor in an extra charge for a new bracelet.

If you are a fan of the retro look and want a large watch to make a statement, then leave it to the Spinnaker Dumas to excite the eye whenever you look at it. Seriously, the dial looks absolutely fantastic and its usability at night is excellent. If you plan on doing plenty of diving, then you should consider the Spinnaker Dumas.

You can find all the Spinnaker Dumas variations here.

Photo Credits: SeriousWatches