NATO Straps Explained: Origins, Fit and Why They Suit the MoonSwatch
Few straps have travelled as far from their original purpose as the NATO. It began as plain British military kit, made to a written specification and issued by the yard, and it has ended up as the band most owners reach for when they want a Bioceramic chronograph to look less like a novelty and more like a tool watch. Everything in our straps for the Omega x Swatch MoonSwatch range fits the same 20 mm lugs, so fitting one is a matter of taste — but the NATO earns its place here for reasons that have little to do with looks.
Where the NATO strap actually comes from
A defence specification, not a design
The strap now universally called a NATO was standardised by the British Ministry of Defence in 1973, under a defence standard describing a nylon band for wear with service watches. The specification was unglamorous and very precise: a single length of woven nylon, 20 mm wide, in a shade recorded as Admiralty Grey, with chrome-plated brass hardware and a second short strip stitched across it. Nothing about it was styled. It was drawn up so that a watch issued to a serviceman could not be lost, and every feature collectors now admire serves that requirement.
Why the name stuck
Soldiers requisitioned the strap on a form numbered G1098, which is why the original grey band is still known among collectors as a G10. The word NATO came from the stock number it was ordered under rather than from anything to do with the alliance. Neither name describes the object accurately, and both have outlived every attempt to correct them.
How a NATO is built, and why the construction matters
One length of nylon, two passes
A conventional two-piece strap attaches independently at each lug: if one spring bar lets go, the watch meets the pavement. A NATO is a single strip that threads under one spring bar, runs beneath the case back and emerges under the other, with a shorter second strip looped through it to hold the free end. When a bar fails, the watch slides along the nylon and stays on the arm. That is the entire idea, and it remains the best argument for the design half a century later.
Hardware, keepers and the extra layer
The rest is deliberately simple: a tang buckle, two or three keeper loops to tidy the tail, and stitched bar-tacks where the strips meet. The price of that security is a layer of nylon between the case back and the wrist, which lifts the watch a millimetre or two and holds warmth against the skin. On a slim dress watch that is a genuine drawback. On a 42 mm chronograph that already stands proud of the wrist, it changes far less than you would expect.
Why it suits the MoonSwatch so well
The spring bars are the honest reason
A MoonSwatch is light, worn hard and fitted with ordinary spring bars, and almost nobody has one serviced. A bar compressed a hundred times during strap changes eventually gives up without warning, usually on a sleeve or a door handle. The NATO removes that single point of failure altogether — worth more, on a watch bought to be worn rather than admired in a drawer, than the material of the band.
It gets the proportions right
The MoonSwatch is a wide case with a shallow profile, and thick straps make it look top-heavy. Nylon is thin, matte and immediately flexible: it wraps on the first wearing and lets the case sit flat rather than perch. It has no shine, which plays down the gloss of the Bioceramic instead of competing with it — one reason a grey or black NATO makes even the loudest Mission look more serious.
Colour without commitment
Very few MoonSwatch dials are subtle, and a nylon band is the cheapest way to answer them. A stripe picked out of the subdial ring, a plain black for the office, a bold colour for the weekend: a woven strap rarely troubles thirty euros, so owning three is a small decision rather than an investment.
Fitting one to a MoonSwatch
The MoonSwatch takes a 20 mm strap, straight-ended, and a NATO needs no tool once the spring bars are in place. The bars stay put, which is the design's second quiet advantage: no repeated compression, no scratched lug holes, no bar lost under the sofa. Thread the long strip under the twelve o'clock bar, beneath the case back and out under the six o'clock bar, then feed the tail through the short keeper strip and back through the buckle.
Two details decide whether the result looks right: the watch should sit centrally on the strap, which means judging how much nylon you leave above the buckle before you tighten anything, and the tail must be trapped by both keepers rather than tucked under itself. A loose tail is what makes a NATO look scruffy rather than military. The NATO straps for the MoonSwatch are all cut to the same 20 mm and need no sizing beyond choosing a length.
Length, thickness and weave
Three specifications separate a good nylon band from a disappointing one, and none appear in most product photographs.
Length. A standard NATO runs around 280 mm. On a wrist under 16 cm that leaves a long tail to hide, and the fix is a shorter cut or a strap with three keepers rather than two. Trimming and sealing the end with a flame works, but it is irreversible and rarely as neat.
Thickness. Around 1.2 mm is the sweet spot. Thinner nylon feels cheap and frays at the buckle holes; much thicker and the double layer under the case back lifts the watch noticeably.
Weave. A tight seatbelt-style weave is smooth, slightly glossy and slides easily through the keepers. A traditional ribbed weave is more matte, more textured and holds its shape better over years. Neither is objectively better, though the ribbed version sits closer to the original.
| Strap type | Security if a bar fails | Bulk under the case | Drying time |
|---|---|---|---|
| NATO nylon | Watch stays on the wrist | One extra layer | Several hours |
| Canvas two-piece | None | None | Four to six hours |
| Rubber two-piece | None | None | Minutes |
| Steel bracelet | None | None | Minutes |
Where a NATO is the wrong answer
Three situations, mostly. Around water, the nylon under the case back stays wet long after the rest of the watch has dried, and a damp layer held there is how corrosion starts on cheap spring bars; rubber is the better choice for the pool and the beach. In real heat, that same layer traps warmth where the wrist is least ventilated. And under a fitted shirt cuff the extra height and the buckle tail can catch — if you want the character of woven fabric without the pass under the case, the canvas straps for the MoonSwatch give you the texture and none of the bulk.
Looking after nylon
Nylon is the most forgiving material on a watch and the slowest to dry. Hand-wash it in lukewarm water with a drop of mild washing-up liquid, squeeze rather than wring so the weave keeps its shape, rinse until the water runs clear, then dry it flat on a towel away from radiators. Allow four to six hours, and never refit it damp.
The two failure points are the buckle holes, which fray with heavy use, and the bar-tack stitching where the short strip is attached. Check both twice a year. A frayed hole can be sealed with a careful touch of heat; failed stitching means the strap is finished, which after three or four years of daily wear is a reasonable innings.
Frequently asked questions
Does a NATO really stop the watch falling off?
Yes, and it is the reason the design exists. Because the strap passes under the case back in one continuous piece, a broken spring bar lets the watch slide along the nylon rather than leave your wrist.
What size NATO does a MoonSwatch need?
20 mm, straight-ended. Every MoonSwatch uses the same lug width, so a strap bought for one model fits all of them.
Does it make the watch sit too high?
Slightly, by one layer of nylon. On a 42 mm case with a shallow profile it is barely noticeable; on a thin dress watch it would be.
Can I swim in a NATO?
The nylon is unbothered, but it holds water against the case back for hours afterwards. Rinse it in fresh water and dry it fully, or keep a rubber band for the pool and the sea.
Ribbed or seatbelt weave?
Seatbelt nylon is smoother and slides more easily through the keepers; ribbed nylon is more matte and closer to the original military band. Purely a question of preference.
The short version
The NATO is one of the very few watch accessories designed around a problem rather than an aesthetic, and the problem it solves — a spring bar giving way on a watch nobody services — is one the MoonSwatch genuinely has. It costs almost nothing, needs no tool, adds no bulk at the lugs and changes the character of the watch entirely depending on the colour. Keep one for security and one for the weekend, save rubber for anything wet, and a strap that began life as grey military issue turns out to be the most practical thing you can put on a Bioceramic chronograph.
Browse the full MoonSwatch straps collection for NATO and other styles.
Also read our previous article: Gifting a Royal Pop Strap: How to Choose for Someone Else