Navy SEAL Foundation XS.3517 a green Luminox diver with two straps

What is new about the Navy SEAL Foundation XS.3517?

Luminox releases a new Navy SEAL Foundation model each year on US Veterans Day, and the XS.3517.NSF.SET was the November 2024 edition. Luminox announced it as a new addition to the Navy SEAL 3500 Series, finished in what it calls military green and yellow. The brand has been an official partner of the Navy SEAL Foundation, a charity that supports veterans and their families, since 2020.

The underlying watch is familiar. The 3500 Series is one of Luminox's core divers: a chunky 45 mm case in the brand's CARBONOX material, a big date at three o'clock, a 24-hour inner track and very large Arabic numerals. What changes here is the colour and the lume. The dial is olive green with black numerals, the bezel has a yellow 0 to 20 minute section, and the tritium tubes are ice blue at the hour markers and yellow at 12, which Luminox says matches the colours of the Foundation's logo. The steel caseback carries the Foundation's emblem.

The other difference is in the box. This is a set, so alongside the fitted black rubber strap you get a black NATO webbing strap at no extra cost.

How big is it, and how will it wear?

Luminox lists the case at 45 mm across and 15 mm high, with a 24 mm lug width. (Watchard, a European dealer, gives the height as 14 mm; we have used the brand's figure.) There is no getting round it: this is a big watch, with wide crown guards and a toothy bezel that make it look broader still.

What softens the size is the material. CARBONOX is a carbon compound that is much lighter than steel, and reviewers of earlier 3500 Series models have consistently described the watch as light and comfortable for its size. The 24 mm strap is wider than most, which suits the case but means fewer aftermarket options than the common 20 mm and 22 mm sizes. The NATO strap in the set gives you a lower, softer alternative on the wrist.

What movement does it use, and how accurate is it?

Inside is a Swiss quartz RONDA 515 with time and date. Luminox quotes a battery life of around 50 months. Luminox does not publish a monthly accuracy figure for this model, but a Swiss quartz movement of this type will keep far closer time than any mechanical diver at the price, and it will not stop if you leave it in a drawer for a week.

The real point of a Luminox is the light. There are 16 self-powered tritium gas tubes on the dial, hands and bezel, and Luminox says they glow constantly for up to 25 years without needing to be charged by light. Painted lume on most divers is bright for an hour and dim by morning; these stay readable through the night. The yellow tube on the bezel pip helps when timing something in the dark.

How well is it built?

The specification is rugged rather than refined. Luminox fits a CARBONOX case and unidirectional bezel, a screw-down crown, a screw-on 316L stainless steel caseback and 200 m of water resistance. The crystal is hardened mineral glass, which Luminox rates at 550 to 650 Vickers. It is Swiss Made.

The mineral crystal is the weak point on paper. Sapphire is standard on many divers at this price, and mineral glass will scratch more easily over years of wear. Deployant's review of the 3500 Series also found that the bezel action, while solid with little play, had a flat and slightly plasticky feel. That is the trade for a light composite case: it does not have the dense, machined feel of steel.

Is it good value against its rivals?

The RRP on Luminox's UK site is £545. The obvious rival is Seiko's Prospex Solar Diver's SNE595P1 at £500 RRP, a 41 mm solar diver with 200 m of water resistance in a steel case that never needs a battery change. Citizen's Promaster Dive BN0261-51E costs £369 and is a smaller, solar-powered ISO diver on a steel bracelet.

On materials alone, both of those give you more for less. Where the Luminox wins is legibility in the dark, a far lighter case, and the second strap in the box. If you need to read the time at night without pressing a button or charging lume in the light first, neither rival does what the tritium tubes do.

What is the catch?

There are three. First, size: 45 mm by 15 mm will overwhelm smaller wrists, even in a light material. Second, the mineral crystal at £545, when rivals at the same money fit sapphire. Third, part of what you pay for is the Foundation link and the special colourway; if those do not matter to you, the plainer black 3500 Series models give you the same case, movement and lume. Luminox also lists a newer Navy SEAL Foundation model, The Guardian XS.3505.NSF.N, at £539, so compare the two before you buy.

“Painted lume fades by morning; these tubes are still glowing at 4am.”

What do owners say?

Themes from public owner feedback, paraphrased. We never copy Amazon reviews or ratings.

• Reviewers of the earlier 3500 Series found the carbon case light and comfortable, but the bezel action flat and slightly plasticky.

  Deployant (opens in a new tab)

• WatchGecko's review of the related 3501 found the dial very easy to read at night and the light case and PU strap comfortable for long wear, though the look is far from subtle.

  WatchGecko (opens in a new tab)