Since its debut in 2023, the Marinor collection from Heron Watch Co. has paid homage to classic dive watch aesthetics, seamlessly blending historical inspiration with modern robustness as if they had been doing it for years. The Marinor has been a staple on several watch guides and best-of lists here on Balance & Bridge, and for good reason. The Canada-based brand has mastered the art of storytelling and product development, which I explored in my review of their first Marinor release.
From the military-inspired ruggedness of the Marinor Ghost to the folklore-infused refinement of the original Marinor Classic, each iteration has a unique chapter of a well-crafted story to tell. Now, the Marinor Rainbow takes the collection into new territory, diving headfirst into the colorful and experimental era of the 1960s with its vintage styling, multi-layered sandwich dial, and functional decompression scale.
A Hands-On Look: First Impressions
Right out of the box, the Marinor Rainbow feels like a celebration of dive watch heritage infused with a playful, eye-catching (but practical) aesthetic. The watch retains the sturdy case shape and tool-watch functionality of its predecessors but injects a serious dose of vibrancy through its rainbow gradient 'sandwich' dial and multicolored decompression scale. It’s bold but not over-the-top—striking a balance between vintage inspiration and modern wearability.
While sandwich dials were a common practice in watchmaking several years ago (I'm looking at you, Panerai), they're not as common today, but Heron is making a statement with their revitalization of the design. A sandwich dial features two layers, with the top layer having cutouts for numerals or markers and the bottom layer often made of luminous material that shines through. This construction enhances legibility in low light, adds depth and texture to the dial, and is often used for both functional and aesthetic purposes.
The Dial & Colors: A Burst of Energy
The dial is the immediate standout here, with its radiant spectrum of colors reminiscent of decompression charts used in vintage dive watches of the 1960s. It’s a mix of function and fun, ensuring legibility while offering a distinctive look that feels both retro and fresh. The applied indices and hands are generously lumed, ensuring visibility in low-light conditions, a crucial feature for divers and everyday wearers alike. The slight sunburst finish adds depth, shifting colors subtly depending on the lighting, which makes it a dynamic piece to admire on the wrist. The vibrancy of the dial, paired with the sapphire bezel and hardened steel case and bracelet, makes for quite a unique pairing.
Specification Round-Up:
Feature | Description |
Material | Hardened Stainless Steel - 1200HV |
Movement | Automatic Miyota 9039 (No Battery Required) |
Crystal | Boxed Sapphire Crystal (AR Coated) |
Bezel | Rotating Domed Sapphire Bezel - 120 Clicks, Uni-Directional, Countdown |
Lume | Swiss Lume: Blue Super-Luminova (BGW9 + Old Radium) |
Case & Bracelet | Brushed Case and Bracelet |
Crown & Caseback | Screw Down Crown & Caseback |
Water Resistance | 300 Meter |
Strap | FKM Tropical Rubber Strap |
Case Size | 39mm (Diameter) X 47mm (Lug To Lug) |
Lug Width | 20mm |
Thickness | 12.9mm (11.3mm w/o Crystal) |
A Tribute to Rainbow Divers
The Marinor Rainbow draws direct inspiration from the vibrant decompression-scale watches of the late 1960s and early 1970s—timepieces from brands like Mido, Buler, and Vulcain that combined bold color palettes with practical diving functionality. These watches weren’t just eye-catching; their multicolored scales served as essential tools for divers, offering a quick visual reference for necessary ascent stops based on depth and time underwater.
Heron captures this heritage with a desaturated yet striking rainbow decompression scale that pays homage to the era while ensuring legibility. This historical touch, paired with the Marinor’s signature skin-diver case, sandwich dial construction for enhanced depth and readability, and no-nonsense utility, makes for a compelling blend of vintage inspiration and contemporary execution.
How the Decompression Scale Works
A decompression scale is crucial for divers who spend extended periods underwater. As they descend, their bodies absorb nitrogen from the air they breathe. Ascending too quickly can cause this nitrogen to form bubbles in the bloodstream, leading to decompression sickness (commonly known as "the bends").
The decompression scale on the Marinor Rainbow is color-coded to provide a quick reference for safe ascent rates. Divers can match their depth and dive time to the corresponding color segment, which indicates how long they should pause at certain depths before surfacing. While modern dive computers have largely replaced these manual scales, their inclusion on the Marinor Rainbow pays tribute to an era when such features were a necessity for underwater explorers.
Functionality: Timing Bezel & Practical Use
This isn’t just a colorful watch—it’s built with real dive functionality. The unidirectional timing bezel, a staple of dive watches, allows you to track elapsed time underwater or for everyday tasks. To use it, simply rotate the bezel’s zero marker (the luminous pip) to align with the minute hand. As time passes, you can read elapsed minutes off the bezel, making it handy for tracking dive times, cooking, or even meetings.
Since the bezel only turns counterclockwise, it prevents accidental adjustments that could result in overestimating available dive time—a small but crucial safety feature.
Case & Wearability: Vintage Proportions, Modern Comfort
The Marinor Rainbow’s 40mm stainless steel case hits that versatile size sweet spot—big enough for a presence on the wrist, but compact enough for comfortable wear. The case finishing is well-executed, with brushed surfaces that keep it tool-like, contrasted by polished chamfers that add a touch of refinement. The 12.9 mm thickness gives it a reassuring presence without feeling bulky, and the curved lugs ensure it sits well on the wrist.
Built for durability, the case and bracelet undergo a hardening treatment, bringing the material up to an impressive 1200 HV on the Vickers scale—essentially making it highly scratch-resistant. A domed sapphire crystal adds both durability and a vintage flourish.
The watch is available with both a stainless steel bracelet and a rubber strap, allowing for versatility. The bracelet feels solid, with well-machined links and a secure clasp, while the rubber strap offers a comfortable, casual alternative—especially useful for actual water use. I love a rubber strap, and the supplied tropic strap sets off the vintage aesthetic and pairs it with incredible comfort. I can see this living on the rubber - especially as we approach the summer months, when wrists tend to swell.
Movement & Performance
Powering the Marinor Rainbow is the trusted Miyota 9039 automatic movement. This reliable workhorse runs at 28,800 bph, offering a smooth sweep, 24 jewels, and a 42-hour power reserve. Known for its dependability and ease of maintenance, it’s a strong choice for a watch meant to be worn regularly.
With 300 meters (1,000 feet) of water resistance, a screw-down crown and caseback, and Swiss Super-LumiNova accents, the Marinor Rainbow is more than just a visual throwback—it’s a serious tool watch built to perform.
Strap Choices and Pricing
The Marinor Rainbow is available in two configurations: a tropical FKM rubber strap version ($570 USD) and a hardened stainless steel bracelet variant ($630 USD). Each watch comes with a precision screwdriver and a premium travel case, ensuring that owners can easily swap between strap options and keep their timepieces secure on the go.
Heron Marinor Rainbow Final Thoughts: A Welcomed & Nostalgic Fresh Take
The Heron Marinor Rainbow had me at sandwich dial and is a perfect example of how a brand can celebrate the past while keeping things exciting for modern collectors. It’s bold without being excessive, functional without feeling like a pure tool watch, and effortlessly stylish. Whether you’re drawn to its historical nods, its vibrant aesthetic, or its robust diving functionality, this is a timepiece that delivers personality and performance in equal measure. It stands out without trying too hard, making it a great option for both vintage enthusiasts and those looking to add some color to their collection.
There are very few new watchmakers taking the risks that Heron is. Their ability to create their own lane, live in it, and expand their collections in a way that makes logical sense is quite impressive. The Marinor line has struck a chord with collectors and enthusiasts alike, driving some incredible interest in the brand. It's been awesome to see their journey and we're happy to be a part of the ride.
Learn more about the Heron Marinor Rainbow below. And as always, thanks for spending a part of your day with us.
Balance & Bridge