Marathon Tritium Watch

What’s the Best Tritium Watch for Nightly Adventures?

Preferred by the military, and highly appreciated by professional divers and outdoorsmen. A tritium watch is a very helpful thing to have when operating in darkness.

In this post, I’ll teach you how it works, and I’ll also show you what I think is the best tritium watch on the market.

Hint; it’s one of these three:

Product Model List Price
Marathon GSAR WW194006 N/A
Luminox EVO Navy SEAL 3051 $395.00
ArmourLite ISOBrite T100 ISO100 $449.00

Scroll down if you want to skip science class…

What is a Tritium Watch?

Let’s start out with the basics. A tritium watch is a watch that uses tritium illumination technology to make it possible to see what time it is in darkness. It’s most commonly used in diver’s watches.

How Does it Work?

To make the hands and hour markers glow in the dark, some sort of luminous paint are most often used. The paint will give off visible light through either fluorescence, phosphorescence, or radioluminescence.

The most effective technology of the three is radioluminescence, a technology that uses the decay of a radioactive isotope to create light. First off was radium, a relatively hazardous material. Due to health concerns, manufacturers were forced to come up with a safer material. Hello tritium!

Tritium (a form of hydrogen) emits beta radiation with only low energy. In other words, it’s safe to use in a watch. It still gives off light for many years though. After its half-life of 12.3 years, it will have lost only 50% of its original luminosity.

Ok, but how does it create light?

The short explanation is spelled GTLS, Gaseous Tritium Light Source. That’s the name of the technology being used, and it works like this:

Small glass tubes are coated with a phosphor material, and then filled with tritium gas. Because tritium is a radioactive isotope, it constantly emits electrons due to beta decay. The emitted electrons then interact with the phosphor coating to create visible light (technically speaking, the phosphor layer will fluoresce).

The glass tubes are typically placed on the hands and hour markers to give a constant low-intensity glow, perfect for telling time at night or deep underwater.

Thanks to a half-life of 12.3 years, watches with tritium gas tubes will give off light for a much longer period of time than watches using phosphorescence.

Advantages of using Watches with Tritium Gas Tubes

There are three major advantages of using the tritium technology described above (GTLS).

  1. Doesn’t require sunlight or artificial light, nor any source of power to function.
  2. Glows for 10-20 years without interruptions.
  3. Reliable. Will not suddenly stop glowing, since it’s “self-powered” (doesn’t require battery, sunlight etc.).

There are other types of illumination technologies on the market. Super-LumiNova and LumiBrite are two competing technologies that are perhaps the most popular. The pair share two distinct disadvantages:

  • They need to be activated by an external source of light
  • The glow fades in a matter of hours

To be fair, they also have advantages over tritium. Primarily brightness. When fully activated, Super-LumiNova and LumiBrite watches glow more intensely than a comparable tritium timepiece. But only for a couple of hours.

Now if brightness is very important to you, you could opt for a watch with a T100 rating. Like the ArmourLite ISOBrite T100 Dive Watch reviewed further down. T100 means that it contains up to 100 mCi of radiation, and that’s the brightest tritium watch you could find.

When adding up all the pros and cons, I think that tritium tube watches is the way to go when choosing a tactical or military watch.

Enough Talk – What’s the Best Tritium Watch?

There are a lot of watches to choose from, but we have narrowed the field down to three excellent candidates.

Marathon WW194006 GSAR Military Issue Diver’s Automatic Watch

The Marathon GSAR (Government Search and Rescue) is a very tough and durable watch. It was built for Search and Rescue divers, but it has also been issued to the U.S. Marine Corps. It actually has its own NATO stock number.

It’s Swiss made, with a scratch-resistant sapphire glass, and it’s water resistant to 300 metres. Best of it all; it has a self-winding mechanical movement, which means you don’t need any battery! It will just keep on going (as long as you move your arm once in a while).

But let’s get to the important stuff; can you tell time in a dark cave? Absolutely! Thanks to its tritium gas tubes, this is what it looks like in the dark:

Pros: Self-winding movement.

Cons: Expensive.

Luminox 3051 EVO Navy SEAL Colormark Watch

The 3051 EVO Navy SEAL Colormark watch by Luminox is a fantastic timepiece. As revealed by its name, this piece of precision engineering was developed for, and together with, the legendary elite unit U.S. Navy SEALs.

We have previously reviewed it as one of the top three tactical watches in the world. And since the 3051 EVO Navy SEAL model utilizes tritium illumination technology (or Night Vision Tubes as Luminox calls it), its really a no-brainer to include it among the top three tritium watches as well.

Water resistant to 200 metres, Swiss quartz movement, and built to withstand war. Wether you are diving in a cave or out hiking at night, you will always be able to tell the time.

It’s simply put a very robust and reliable watch that won’t let you down.

Pros: Low price. Reliable.

Cons: Needs a battery.

ArmourLite ISOBrite T100 Super-Bright Dive Watch

ArmourLite is a less famous brand than Luminox and Marathon, but make no mistake. It’s an up-and-coming brand that makes very competitive watches. Just take a look at the ISOBrite T100 Super-Bright Dive Watch!

This model is rated T100, which means that it’s four times brighter than the two other watches in this post. Now, most people would call that an overkill, since both the Marathon and the Luminox timepiece are bright enough. But hey, if you want a REALLY luminescent watch, this one is for you!

The ISOBrite T100 has a lot of things going for it. Just like its competitors, it’s water resistant (to 200 metres), and it’s got a sapphire crystal dial window.

Having a highly durable silicone watch band, along with a Swiss quartz movement from Ronda is also nice. But what makes it special, in my opinion, is that the case and bezel are made of polycarbonate, meaning that it’s lightweight. No need for a heavy and bulky thing on your wrist!

With a whopping 4.8 rating (on a scale 1-5), Amazon customers absolutely love this watch. And so do we.

Pros: Very bright. Lightweight.

Cons: Needs a battery.

And the Best One is?

Ok, I guess it’s time to reveal the winning candidate. All three are excellent watches, but if money was of no concern, I’d pick the Marathon GSAR watch as the best tritium watch. I think the self-winding movement is a huge thing, that really sets it apart from the other two.

But if price has to be factored in, the outcome is different. On a tighter budget I would have to choose the Luminox Navy SEAL watch. Apart from the need of a battery, it’s just as good as the Marathon, but at a fraction of the price. Very affordable!