Water & Dive
Purposeful watches with strong legibility and model-specific water resistance, including the famous Navy SEAL families.
Marcus Tempus
Product Story
Created as a tribute to the enduring strength, resilience and determination associated with the U.S. Navy, the Luminox Navy SEAL SEMPER-FORTIS is a striking limited edition of just 775 individually numbered watches worldwide.
Built around Luminox's iconic 45mm Navy SEAL 3500 design, the XS.3515.N is constructed almost entirely from lightweight CARBONOX™. The case, unidirectional rotating bezel and even the bracelet use the material, creating an imposing all-black watch without the weight normally associated with a substantial metal bracelet. At just 93g, it remains remarkably wearable.
The stealth-black dial carries the words “SEMPER-FORTIS” — Ever Strong, with the red inscription providing the principal flash of colour. As the light fades, the SEMPER-FORTIS detail glows with Super-LumiNova®, while Luminox Light Technology provides constant self-powered visibility for up to 25 years.
A Swiss Ronda 515 quartz movement provides dependable time and date functionality, while a screw-down crown, 200-metre water resistance and hardened mineral crystal give the watch genuine everyday durability. It's a particularly distinctive interpretation of the Navy SEAL collection — stealthy, purposeful and genuinely limited.
Features
Model: Luminox Navy SEAL SEMPER-FORTIS XS.3515.N
Series: Navy SEAL 3500
Limited Edition: 775 individually numbered pieces worldwide
Swiss Made
Movement: Swiss Ronda 515 quartz
Functions: Time and date
Case: CARBONOX™
Case Diameter: 45mm
Case Height: 14mm
Bezel: CARBONOX™ unidirectional rotating bezel
Crystal: Hardened mineral crystal
Crown: Screw-down crown
Case Back: 316L stainless steel, screw-on
Illumination: Luminox Light Technology, constant glow for up to 25 years
Dial Detail: Super-LumiNova® SEMPER-FORTIS inscription
Water Resistance: 200 metres / 660 feet / 20 ATM
Bracelet: Black CARBONOX™
Lug Width: 24mm
Buckle: 316L stainless steel
Weight: 93g
Marcus Tempus Brand Passport
MT-BP-002
Swiss Performance Watches
Luminox
Brand Passport • Swiss Made • Since 1989Founded1989
WatchmakingSwiss Made
Signature TechnologyLuminox Light Technology
IlluminationSelf-powered for up to 25 years
Performance HeritageNavy SEAL collaboration
Design WorldSea • Air • Land
Performance on the Wrist
Made to Be Read at a Glance
Luminox watches combine strong dial contrast, practical case construction and highly visible markers with a distinctly purposeful design language.
The result is a watch that feels equally at home outdoors, on the water or in everyday life — with the visual character to remain unmistakably Luminox.
The Technology
Luminox Light Technology
Luminox Light Technology uses tiny borosilicate glass capsules containing micro gas lights on the hands, hour markers and, on selected models, the bezel.
Unlike conventional luminous paint that must first absorb light, LLT is self-powered and designed to provide continuous visibility for up to 25 years.
24/7
Visibility without external charging
A Defining Chapter
The Navy SEAL Connection
In 1992, Navy SEAL research and development officer Chief Nick North worked with Luminox to develop a watch suited to the demanding needs of the SEALs.
That collaboration helped establish the Original Navy SEAL 3000 Series and became one of the most recognisable parts of the Luminox story.
Purposeful Materials
CARBONOX™
CARBONOX™ is Luminox's carbon-based case material, developed for watches where low weight and robust construction matter.
Luminox describes CARBONOX™ as six times lighter than steel and three times lighter than titanium, while also being non-metallic, anti-magnetic and resistant to changing weather conditions.
The Luminox World
Sea. Air. Land.
Aviation Influence
Watches inspired by cockpit clarity, technical readability and the practical requirements of aviation.
Outdoor Performance
Rugged watches designed for everyday adventure, field use and reliable visibility beyond the city.
Choosing Your Watch
Specifications Vary by Model
Luminox collections include different case materials, movements, crystals, case sizes and levels of water resistance. Some models use quartz movements while others are automatic.
We therefore list the exact technical specification on each Marcus Tempus product page rather than applying one specification to the whole brand.
Care & Water Resistance
Keeping a Luminox Ready for Use
Water resistance is not permanent. Luminox recommends that gaskets are inspected and replaced every 18–24 months, or more frequently when a watch is regularly exposed to chlorinated pools or salt water. The exact water-resistance rating should always be checked on the individual model.
Luminox Questions
Frequently Asked Questions
What is Luminox Light Technology?
It is a self-powered illumination system using micro gas lights inside tiny glass capsules to provide continuous low-light visibility.
How long does LLT last?
Luminox states that its self-powered illumination is designed to remain visible for up to 25 years.
Do Luminox watches need light to charge?
No. LLT does not rely on external light to charge in the way conventional luminous paint does.
What is CARBONOX™?
It is a lightweight carbon-based material used by Luminox on selected watch cases and components.
Are all Luminox watches waterproof to the same depth?
No. Water resistance varies by model, so the individual watch specification should always be checked.
Are all Luminox watches quartz?
No. The range includes quartz watches as well as selected automatic models.
Explore Luminox
Discover the Collection
Explore our current Luminox watches online, or visit Marcus Tempus to see selected models in person.