Lum-Tec Solar Marine 5 | USA Assembled Solar Dive Watch with MDV Lume

The Lum-Tec Solar Marine 5 combines solar power and a 300-meter water-resistance rating in a compact 39 mm case. Its brushed and polished steel finish, semi-transparent black solar dial, and rotating bezel give it a straightforward dive-watch look. At 10.7 mm thick and 43.5 mm lug to lug, it is built for everyday wear.

The Japanese VS42A solar movement provides approximately six months of running time on a full charge. Sapphire crystal, BGW9 Super-Luminova as part of Lum-Tec's MDV® luminous technology, and a nylon strap with matching steel hardware are included. Hand assembled and tested in Mentor, Ohio, it is limited to 300 numbered pieces worldwide and sold new by The CGA Company with free USA shipping.

Lum-Tec brought back the Solar Marine series after steady demand from owners, updating and upgrading it for 2026. Lum-Tec says the series was designed from scratch as an everyday companion: a smaller 39 mm case, light weight, a symmetrical dial and a solar-powered movement. Lum-Tec calls it a multi-purpose dive watch, with a 300 meter rating and a clean, legible design that it says has made the series a fan favorite.

On the VS42A, about a minute of sunlight provides a day of running, and roughly five hours of sun fills it for a six-month reserve.

Specifications

• Case width: 39 mm, forged and heat-treated 316L surgical-grade stainless steel
• Thickness: 10.7 mm including sapphire
• Lug to lug: 43.5 mm
• Lug width: 20 mm, drilled lugs for easy strap changes
• Finish: Brushed and polished, with anti-fingerprint coating
• Bezel: Rotating, with steel insert and luminous pip
• Water resistance: 300 meters
• Movement: Japanese VS42A solar quartz
• Charging: About 1 minute of sunlight gives a full day of power; a full charge (about 5 hours of sunlight) gives a 6-month power reserve
• Shock protection: Anti-shock movement mounting system
• Crystal: 2 mm sapphire with military-grade AR coating on both sides
• Caseback: Threaded solid 316L stainless steel
• Crown: Threaded 316L steel, double Viton® seals
• Gaskets: Viton®
• Dial: Semi-transparent black solar dial, grade A BGW9 Super-Luminova with metal-framed indices
• Hands: Diamond-cut, filled with A-grade BGW9 Super-Luminova
• Lume: MDV® luminous technology on dial and hands
• Strap: Nylon military-style strap with matching 316L stainless hardware
• Warranty: 2-year limited warranty
• Edition: Limited and numbered, 300 pieces worldwide
• Assembly: Designed, assembled by hand and fully tested in Mentor, Ohio

Construction

The case is forged from 316L steel and heat treated. Lum-Tec says forging adds about 37% fatigue strength over a typical cast case. It is brushed and polished by hand and then given an anti-fingerprint coating to keep smudges off the finish.

The 2 mm sapphire sits in a Hytrel mount and is AR coated on both faces. The threaded crown and solid caseback use silicone-lubricated double Viton® seals, and Lum-Tec says the sealing is tested to 30% beyond the 300 m rating. An anti-shock mount protects the movement.

Heat treatment keeps the steel stable while it is forged and hardens the surface after finishing. The case seals are meant to resist salt water, chemicals and extreme heat or cold as well as depth, and the anti-shock mount helps the solar movement ride out an accidental drop or a hard knock.

Strap and Fit

The Solar Marine 5 is 39 mm wide, 10.7 mm thick and 43.5 mm lug to lug, so it is light and wears well on most wrists. The thick nylon strap loops through both spring bars, so the watch stays on if one fails. Drilled lugs make it easy to swap in another 20 mm strap.

Lum-Tec says its nylon straps are more durable than typical straps of this type and are designed for easy adjustment, a secure fit and minimal weight on the wrist.

MDV® Lume

The metal-framed markers and the hands use grade A BGW9 Super-Luminova, printed in more than 30 layers over a reflective base so the light is sent forward. The bezel has a luminous pip for timing dives. Lum-Tec says RcTritec in Switzerland verified its dials as top Super-Luminova performers.

Lifetime Service

The movement is solar powered, so there are no routine battery changes. Lum-Tec provides free seal cleaning, lubrication and pressure testing for life, in Ohio. Lum-Tec says it regularly sees its watches come back for service after 15 or more years of use, and it puts what it learns from them into new designs. Lifetime services are provided by Lum-Tec under Lum-Tec's terms, not by The CGA Company; for service, contact service@lum-tec.com.

Hand Assembled and Tested in Mentor, Ohio

Lum-Tec says its watches are designed and engineered in Ohio from the ground up, and every Solar Marine 5 is hand assembled and individually tested in Mentor, Ohio, using international and domestic components; the movement in this model is the Japanese VS42A solar quartz. Lum-Tec says that since 2007 it has produced watches for more than 100 brands around the world, the U.S. government and SWAT teams.

Frequently Asked Questions

How is the Solar Marine 5 different from the Solar Marine 6?
The Solar Marine 5 has a brushed and polished steel case with steel strap hardware. The Solar Marine 6 has a bead-blasted black titanium carbide PVD case with black hardware.

Does it need battery changes?
No routine changes. About a minute of sunlight gives a day of power, and a full charge gives about a 6-month power reserve.

How water resistant is it?
300 meters, with a rotating bezel, a threaded crown and a solid threaded caseback.

What lume does it use?
MDV® luminous technology with grade A BGW9 Super-Luminova on the markers and hands, plus a luminous bezel pip.

Where is the Solar Marine 5 assembled?
Lum-Tec hand assembles and tests every Solar Marine 5 in Mentor, Ohio, using international and domestic components. The movement is the Japanese VS42A solar quartz.

Comparing Solar Marine models? See how the Solar Marine 5, 6, 7 and 8 compare on size, finish, and charging.