The Marathon GPQ-D is a 34mm Swiss quartz field watch with T25 tritium illumination, a sapphire crystal and a lightweight Fibreshell case. I bought mine because I wanted a compact Marathon that retained the company’s military field-watch character without the size and weight of the larger SAR models. After wearing it for some time, what stands out most is how unobtrusive it is: at roughly 30 grams, the GPQ is one of those watches you can wear all day and almost forget is there, while the tritium remains available whenever you need to read the time in darkness.
Marathon GPQ-D Specifications
| Specification | Marathon GPQ-D |
|---|---|
| Model | GPQ-D — General Purpose Quartz, Date |
| Case diameter | 34 mm |
| Case thickness | Approximately 11 mm |
| Case material | Fibreshell high-impact composite |
| Weight | Approximately 30 g |
| Lug width | 16 mm |
| Crystal | Sapphire |
| Movement | ETA F06 high-torque Swiss quartz |
| Accuracy | ±20 seconds/month |
| Battery life | Approximately 5 years |
| Dial | 12/24-hour format with date |
| Date | Approximately 4:30 |
| Illumination | Tritium gas tubes |
| Water resistance | 3 ATM / 30 m |
| Strap | 16 mm nylon DEFSTAN |
| Origin | Switzerland |
| Military specification | MIL-PRF-46374G, Type I, Class 1 |
The specifications in the existing article identify the GPQ-D as a 34 mm Fibreshell watch weighing approximately 30 grams, with an ETA F06 high-torque quartz movement, sapphire crystal, tritium illumination and 3 ATM water resistance. The listed battery life is approximately five years, with an end-of-life indicator.
Why I Bought the Marathon GPQ
I bought the GPQ because I wanted a Marathon that was genuinely compact.
The larger Marathon watches are attractive, but they occupy considerably more wrist space and have a very different presence. The GPQ appealed to me because it retains the basic military field-watch concept while reducing the size and weight dramatically.
The 34 mm case was also part of the attraction. That is small by contemporary men’s-watch standards, but I don’t regard that as a disadvantage in this particular design because the GPQ is supposed to be an unobtrusive field watch rather than a statement piece.
The result has been exactly what I was looking for. The GPQ is small, light, easy to read and sufficiently rugged for normal everyday use, and I have found myself wearing it precisely because it doesn’t demand attention.
The 34 mm Fibreshell Case
The GPQ-D uses Marathon’s Fibreshell high-impact composite case.
At approximately 34 mm across and only about 11 mm thick, it is considerably smaller than watches such as the Marathon GSAR and TSAR. The listed weight of approximately 30 grams makes the difference even more dramatic, particularly when compared with conventional stainless-steel field and dive watches.
I found the watch so light that I would sometimes forget I was wearing it. That is exactly the quality I want from a field watch that is intended to be worn throughout a long day.
There is also something interesting about the physical shape of the case. I find myself occasionally running my fingers over the sides because of the steep case walls and the way the Fibreshell feels in the hand. It is an unusual detail to appreciate, but it contributes to the character of the watch.
A Small Watch With a Surprisingly Deep Dial
The GPQ’s compact dimensions don’t mean that the dial feels cramped.
One of the things I particularly like about this watch is the apparent depth of the dial. Marathon needs sufficient depth inside the case to accommodate the tritium tubes used in the hands, and that creates a noticeable three-dimensional effect when looking down through the crystal.
The effect is difficult to appreciate from a specification sheet, but it gives the otherwise utilitarian dial some visual character. The numerals, hands and tritium tubes appear to sit within a deeper structure rather than simply being printed on a flat surface.
That is one of those small details that makes the GPQ more interesting to own than its simple military styling might suggest.
The 12/24-Hour Dial
The GPQ uses the familiar Marathon 12/24-hour field-watch layout.
Large Arabic numerals provide the primary hour display, while smaller 24-hour numbers sit inside the main numerals. The date window is positioned around 4:30, keeping it away from the main visual axis of the dial.
The layout is highly functional rather than decorative. There is very little on the dial that doesn’t have a purpose, which is appropriate for a watch derived from a military specification.
I also like the fact that the relatively small case doesn’t compromise the basic readability of the dial. The GPQ may be compact, but it doesn’t feel like a miniature version of a larger watch.
Tritium Illumination
The GPQ uses tritium gas tubes rather than conventional photoluminescent paint.
This is one of the most useful features on the watch because the illumination remains available throughout the night without needing to be charged by sunlight or another external light source. The existing specifications describe the illumination simply as self-powered tritium gas tubes providing a constant glow.
The GPQ uses T25 tritium, so the illumination isn’t intended to produce the intensity of a T100 watch. That distinction is important when comparing it with some of the newer tritium watches in my collection.
I don’t consider that a problem on the GPQ because the watch’s purpose is different. It is a compact field watch where consistent nighttime visibility is more important than producing the strongest possible tritium glow.
What the GPQ Looks Like at Night
The GPQ’s tritium is particularly effective because the dial is so uncluttered.
There aren’t unnecessary complications competing for attention, and the illuminated hour markers and hands stand out clearly against the dark dial. The tritium isn’t as immediately dramatic as the stronger T100 watches I own, but it remains visible whenever I need to check the time at night.
That consistency is the real advantage.
A conventional painted lume can look spectacular immediately after being exposed to light and then gradually become less useful. The GPQ takes the opposite approach, providing a modest but persistent glow throughout the night.
Sapphire Crystal
The GPQ-D represents an important improvement over older versions of the watch because this version uses sapphire crystal.
The existing specifications identify sapphire as an upgrade from the acrylic crystals used on older versions.
For me, this is a meaningful upgrade rather than simply a specification-sheet improvement. A field watch is likely to encounter desks, doorways, equipment, tools and outdoor environments during normal use, so scratch resistance matters.
The sapphire also helps preserve the clarity of the dial over time, which is particularly important on a watch where legibility is one of the primary design objectives.
Water Resistance Is the GPQ’s Major Limitation
The GPQ-D is rated to only 3 ATM / 30 meters.
That is enough for ordinary splash resistance and daily wear, but it is not a swimming or diving specification. The existing article correctly describes the watch as suitable for daily wear and light outdoor use rather than as a dive watch.
This is one of the most important differences between the GPQ and Marathon’s larger SAR watches.
If you need substantial water resistance, the GSAR or TSAR makes much more sense. The GPQ is better understood as a land-oriented field watch where compactness and low weight take priority over water resistance.
ETA F06 Quartz Movement
The GPQ-D uses an ETA F06 high-torque Swiss quartz movement.
Quartz is exactly what I want in this particular watch. The GPQ is a grab-and-go field watch, and I don’t want to think about winding it, maintaining a power reserve or resetting it after leaving it unworn for several days.
The listed accuracy is approximately ±20 seconds per month, while the battery life is approximately five years and includes an end-of-life indicator.
That combination makes the GPQ particularly convenient. Pick it up, put it on and go; there is very little else to think about.
Why I Prefer Quartz Here
I own automatic watches and appreciate the mechanical aspect of them, but the GPQ illustrates why I continue to like quartz.
This isn’t a watch I bought for its mechanical character. I bought it because I wanted a compact, practical tool watch that would be ready whenever I needed it.
The ETA quartz movement supports that purpose extremely well. There is no need to wind it, no power reserve to monitor and no concern about the watch stopping simply because I wore something else for a few days.
For a field watch this simple, that practicality is a major advantage.
Wearing the GPQ
This is where the GPQ really works for me.
The approximately 30-gram weight is almost insignificant compared with a conventional steel watch, and the compact case makes it easy to wear for an entire day without becoming aware of it. The original article describes exactly that experience, noting that the watch can effectively disappear on the wrist.
That is particularly noticeable during long days or in hot weather.
I have worn the GPQ while hiking and during long days out, and its light construction makes it much less noticeable than heavier watches. The Fibreshell case doesn’t have the substantial feel of stainless steel, but that is also the reason the GPQ is so comfortable.
The Stock Strap
The supplied strap is a 16 mm nylon DEFSTAN strap.
It is perfectly functional, but it isn’t my favourite configuration. I have swapped the original strap for both a NATO and a Marathon NAV strap, and I have found both alternatives comfortable on the watch.
The narrow 16 mm lug width does limit the range of straps compared with the more common 20, 22 or 24 mm dimensions found on larger watches.
That said, the small strap is consistent with the GPQ’s compact proportions. A wider strap would probably make the watch look less balanced.
What I Like About the Marathon GPQ
The size and weight are the biggest advantages for me. At 34 mm and approximately 30 grams, the GPQ is exceptionally unobtrusive, and that makes it easy to wear for long periods without fatigue.
I also like the military field-watch design. The dial is functional, the 12/24-hour format is useful and the overall appearance avoids unnecessary decoration.
The tritium illumination works exactly as I want it to for this type of watch. It isn’t trying to compete with a T100 dive watch for sheer brightness, but it provides dependable nighttime visibility without requiring the dial to be charged first.
The sapphire crystal on the GPQ-D is another significant advantage over older GPQ versions, particularly for a watch I actually wear outdoors.
Finally, the quartz movement suits the purpose of the watch extremely well. It is simple, accurate enough for everyday use and requires very little attention.
What I Don’t Like
The biggest limitation is obviously the 3 ATM water resistance.
I am comfortable wearing the GPQ in normal daily conditions and while hiking, but I wouldn’t treat it as a swimming watch. That limitation needs to be understood because the Marathon name and military styling can make it easy to assume that every Marathon watch has the water resistance of the company’s SAR models.
The 34 mm case will also divide buyers. I think the size is one of the GPQ’s strengths, but someone accustomed to 40–45 mm watches may find it surprisingly small.
The Fibreshell case also doesn’t provide the same tactile impression as stainless steel. That isn’t a durability criticism, but if you specifically want the weight and feel of a metal case, the GPQ isn’t going to provide it.
Marathon GPQ vs. Marathon NAV-D
I own both the GPQ and a Marathon NAV-D, and the comparison illustrates the different purposes of the two watches.
The GPQ is the more compact and unobtrusive field watch. The NAV-D gives you a larger case and a different pilot-watch configuration, while retaining the lightweight philosophy that makes Marathon’s composite watches interesting.
For everyday wear when I want something that essentially disappears on the wrist, I find the GPQ particularly appealing. The NAV-D is the better choice when I want a larger watch with more presence.
The GPQ’s 3 ATM water resistance also makes it much more specialized toward land use than the NAV-D. That distinction is worth keeping in mind when choosing between them.
Marathon GPQ vs. GSAR and TSAR
The GPQ occupies a completely different part of the Marathon range from the GSAR and TSAR.
The GSAR and TSAR are substantially larger 41 mm dive watches with 300-meter water resistance, while the GPQ is a 34 mm field watch rated to only 30 meters. The larger watches are designed around serious water resistance and greater wrist presence, whereas the GPQ emphasizes compactness, low weight and everyday practicality.
The movement choice is also different in character. The GPQ uses quartz, while the GSAR is an automatic and the TSAR is a larger quartz dive watch.
For me, the GPQ isn’t a cheaper substitute for the larger Marathons. It is a different kind of watch that happens to share the same military-oriented design philosophy.
Who Is the Marathon GPQ For?
The GPQ is particularly well suited to someone who wants a small, lightweight military-style field watch with tritium illumination.
It also makes sense for someone who values quartz convenience and wants a watch that can be worn for long periods without becoming physically noticeable. The 34 mm case and approximately 30-gram weight make that combination unusual among modern men’s field watches.
It is less suitable for anyone who wants substantial water resistance, a large wrist presence or a mechanical movement. Those buyers should be looking at Marathon’s larger models instead.
The GPQ is at its best when its limitations are understood as part of its purpose rather than treated as shortcomings relative to a completely different watch.
Is the Marathon GPQ a Good Tritium Watch?
For a compact field watch, I think the GPQ makes a lot of sense.
Its T25 tritium isn’t exceptionally bright compared with higher-output T100 watches, but that isn’t really the point. The advantage is that the illumination remains available throughout the night rather than fading away like conventional lume.
The combination of a simple black dial, large numerals, tritium markers and illuminated hands produces the kind of functional nighttime readability I expect from a military-style field watch.
The GPQ-D also improves on older versions with its sapphire crystal, giving the watch better scratch resistance without changing the basic character that makes the GPQ appealing.
Final Thoughts
The Marathon GPQ-D is one of the most specialized watches in my collection, but that is also why I like it.
It isn’t trying to compete with the GSAR or TSAR on water resistance, size or mechanical sophistication. Instead, it takes the basic military field-watch concept and reduces it to something remarkably compact, light and unobtrusive.
The 34 mm Fibreshell case and approximately 30-gram weight are the defining characteristics for me. The watch is so easy to wear that I can forget it is there, while the tritium ensures that it remains useful when I need to check the time in darkness.
The GPQ-D also has some details that make it more interesting than its simple appearance suggests. The deep dial created to accommodate the tritium tubes gives the watch an unusual three-dimensional quality, while the sapphire crystal is a worthwhile upgrade over older acrylic versions.
The 3 ATM water resistance is the obvious limitation, and the 34 mm size won’t suit everyone. For me, however, those characteristics are acceptable because they come with the qualities I actually wanted when I bought the watch: small size, extremely low weight, quartz simplicity, military field-watch design and always-available tritium illumination.
That combination is what makes the GPQ worth keeping in my collection.
