Seiko Prospex SPB237 Review | The Grey Birch Captain Willard
The Quick Take
The Seiko Prospex SPB237, often called the “Grey Birch Willard,” is one of the most charming modern Seiko divers. At $1,300 retail (now around $700 on the secondary market), it’s not cheap, but it delivers history, character, and a gorgeous textured gray dial that few watches in this range can match. The strap is bulky, the crown unsigned, and some will gripe about value, but for fans of Seiko’s legendary Captain Willard lineage, this one is a must-own.
Some watches you plan to buy and some sneak up on you. For me the Seiko Prospex SPB237, better known as the Grey Birch Captain Willard, falls into the second category.
I originally set out to buy the blue on blue SPB183 Willard. I handled it at Arizona Fine Time and to my surprise I didn’t like it. It felt off on the wrist, thicker and less refined than I wanted. I walked away. But a few months later I couldn’t shake the itch for a Willard reissue. That’s how the SPB237 with its textured grey dial ended up in my collection.
It wasn’t the watch I planned to buy but it’s the one that stuck.
Why the Willard Matters
The Willard’s reputation needs no introduction. The original 6105 was immortalized on Martin Sheen’s wrist in Apocalypse Now and became a symbol of ruggedness in wet, unforgiving environments. The modern reissues try to capture that spirit, but not all of them succeed.
This SPB237 gets closer than most. Yes it was expensive at retail when it debuted in 2021 at $1,300, but on the secondary market you can now find it around $700 and at that price it becomes a serious contender.
The Dial
Seiko dials are often the reason you buy their watches and this one is a standout. The textured grey surface, nicknamed Grey Birch, is subtle and organic. In direct light it has a shimmer, in softer light it looks distressed and stone-like. It never feels flat.
The hands split between brushed and polished surfaces catch the light beautifully. The lume is classic Seiko Lumibrite, strong and even, and applied with just a touch of warmth. It feels vintage without being faux or heavy handed.
This dial is the reason the SPB237 stands out. It does not scream for attention, it rewards it.
Case and Wearability
The case measures 42.5 millimeters wide, 13.2 thick, with a lug to lug of 46.7. On paper it sounds large, but the cushion case keeps it balanced. The asymmetrical crown guard that divides opinion is what makes the watch so comfortable. It hugs the wrist, avoids snagging, and feels different from every other diver in the box.
The case has a mix of brushed and polished surfaces, protected by Seiko’s Diashield coating. It isn’t scratch proof but it resists wear better than bare steel. The domed sapphire crystal distorts slightly at angles and has anti-reflective coating underneath for legibility in direct sun.
Straps and How I Wear It
Out of the box the SPB237 comes on a thick Seichu woven strap. It looks cool but adds unnecessary bulk. On my wrist it felt tall and clumsy. I swapped it to a simple NATO and the watch immediately came alive. The thinner strap drops the profile and makes the watch feel like the rugged tool it was meant to be.
If you buy one, plan to change the strap. It makes all the difference.
The Movement
Inside beats the Seiko 6R35, a dependable movement with a 70 hour power reserve. It hacks, hand winds, and runs at 21,600 vibrations per hour. Mine keeps around plus eight seconds a day, which is fine for a daily wearer.
It is not the most exciting caliber, and accuracy can vary, but it is reliable. You are not buying this watch for the movement. You are buying it for the case shape, the history, and that dial.
Why It Works
What keeps me reaching for the SPB237 is its balance of charm and practicality. The retail price is hard to swallow, the stock strap is a miss, and the movement is average, but none of that kills the watch.
Instead the Grey Birch thrives on character. It feels vintage inspired without being a copy. It is rugged enough for everyday wear and stylish enough to sit alongside more expensive divers. Most importantly it makes me want to wear it, and that is the true test of any watch.
Verdict
Yes, you should buy it.
At full retail the SPB237 is a tough sell. On the secondary market it is one of the most compelling modern Seiko divers available. For around $700 you get one of Seiko’s best modern dials, a historic case design, and a watch that feels every bit as special on the wrist as it looks in photos.
I have owned plenty of Seiko divers, and while many came and went, the Grey Birch Willard is one I do not regret for a second. It is the Willard that finally clicked for me.
If you have been circling the reissues, this is the one worth pulling the trigger on.
Blair Witkowski is an avid watch nut, loves pocket knives and flashlights, and when he is not trying to be a good dad to his nine kids, you will find him running or posting pics on Instagram. Besides writing articles for Tech Writer EDC he is also the founder of Lowcountry Style & Living. In addition to writing, he is focused on improving his client’s websites for his other passion, Search Engine Optimization. His wife Jennifer and he live in coastal South Carolina.