Seiko Prospex SPB143:
the reissue Seiko already moved past.

Seiko has discontinued the Prospex SPB143, quietly enough that most of the watch press only noticed once the replacement showed up wearing a new reference number. Checked against Seiko’s own US site today, the SPB143 is gone from the current Prospex lineup. The three watches that filled the gap cost more and do more. That is not a reason to skip this review. It is the reason to write one: what does the watch that started the modern 62MAS obsession actually cost you now that Seiko has moved on, and does it still beat the thing that replaced it?

The case for it is unchanged by the calendar

The original 62MAS from 1965 traded on one fact: it was the first Japanese dive watch anyone actually trusted underwater, cushion case and all. Collectors spent a decade asking Seiko to sell that shape back to them properly rather than as a loose homage wearing the name, and the SPB143 was the model that finally did it, not a five digit budget reissue but a full Prospex execution with the finishing to match the reputation.

None of the reasons that made it the default recommendation in this class have gone anywhere just because Seiko stopped shipping it. The case runs 40.5mm across, per Seiko’s own published figure, 47.6mm lug to lug, 13.2mm thick, proportions pulled from the original and quietly resized for wrists that actually exist today. One retailer still selling the watch lists the case at 40mm rather than 40.5mm; that discrepancy is worth naming rather than letting a single retailer’s listing quietly override what Seiko itself published. Inside, a 6R35 automatic banks 70 hours, which in practice is the difference between picking the watch up on a Monday already stopped and picking it up still running from Friday. The water resistance is rated 200m under Seiko’s own “Diver’s” designation, sitting under a sapphire crystal with anti reflective coating rather than the plastic Hardlex some cheaper Seiko divers still ship with. The bracelet is steel, three link, 20mm at the lugs, matching the width of the strap the watch also ships on. The dial itself is a sunburst grey with luminous markers and hands, per the same retailer listing that confirms the price below, since Seiko’s own product page for this exact reference no longer resolves.

The finishing is where the extra money over a five digit Seiko diver actually goes. Zaratsu style polishing runs along the case flanks, the hour markers are applied rather than printed, and the crown sits tucked in close enough to the case to spare your wrist the classic Seiko knuckle knock. None of that shows up as a line on a spec sheet, and all of it is the reason people kept recommending this specific reference years after Seiko had newer divers to sell instead.

The spec sheet reads fine. The calendar is the problem.

Here is the complication a review written two years ago would not have needed to address. Fratello’s own coverage names the SPB451, SPB453 and SPB455 as the successor line to the SPB143, and Seiko’s current US Prospex catalogue backs that up by omission: search it today and the SPB143 simply is not there. The SPB453, the closest analogue in a black dial, runs a 6R55 movement rather than the 6R35, banks a published 72 hours against the SPB143’s 70, and carries a 300m water resistance rating against 200m. Seiko also moved the date window from 3 o’clock to 4:30 and swapped the machined, black coated steel bezel for a satin finished aluminum one, a change more than one reviewer has counted as a step sideways rather than up. The new watch launched at $1,300, a hundred dollars over the SPB143’s own $1,200.

So the honest accounting: the successor buys a hundred more meters of rated depth and two more hours of reserve, and asks you to give up a bezel material and a date position plenty of owners actually preferred. Whether that trade reads as progress depends entirely on which of those four details you care about, and it is a far closer contest than the word “successor” usually implies.

The number worth checking on the SPB143 itself is not the spec sheet. It is the price tag, and I checked it today. Exquisite Timepieces, an authorized dealer, still lists the SPB143 at $1,200, sitting exactly inside the $1,100 to $1,200 band this site’s Atlas entry already recorded. It also shows the watch unavailable to actually buy: out of stock, with a pre order inquiry the only option. That dealer won’t sell you one today at that number, and secondary market listings for this reference were not machine verifiable at the time of writing, so this review does not put a number on what a used example currently costs.

What it is not

It is not a watch with a micro adjust clasp, and that omission costs more on a 200m diver than it would on a dress piece. A rotating bezel and a real depth rating invite you to size the bracelet over a wetsuit sleeve one day and a bare wrist the next, and the fold over clasp here gives you exactly one setting to do both jobs in. If Seiko fixed a single thing on the next reissue, this is the fix that would matter most.

It is not, any longer, a current production watch you order from Seiko the way you would order the SPB453 today. The dealer checked for this review is selling remaining stock rather than restocking, and once that stock clears, the SPB143 becomes a secondary market watch carrying secondary market pricing, at a level this review cannot confirm with a source that opened to automated verification.

It is not the value pick in its own category, either, and this site’s own Atlas entry for the watch says so plainly. The Citizen Promaster NY0086 clears the same 200m diver brief for a fraction of the outlay: a 42mm case, a Citizen Caliber 8204 automatic banking 42 hours, and 20 bar of water resistance, all confirmed on Citizen’s own EU storefront today, though the WatchHypeHQ Atlas entry for this same reference lists the caliber as an 8203, a mismatch worth naming rather than picking a side silently. List price runs $325, and one retailer checked the same day sells it at $160.67, roughly half off. What the Seiko buys over that watch is finishing you can see under a loupe and nearly thirty extra hours of running time off the wrist. Whether that gap is worth roughly a thousand dollars more is a question about your bank account rather than about either watch.

So, worth the hype?

Conditionally, and the condition is availability rather than quality. As a piece of design, the SPB143 has not been beaten by its own replacement so much as sidestepped by it: more depth rating and two more hours of reserve for a hundred dollars more, at the cost of a bezel finish and a date position plenty of owners on record preferred in the first place. If dealer stock or a clean secondary market example turns up anywhere near that $1,200 line, buy it without a second thought. It is still the sharpest execution of the 62MAS shape Seiko has shipped, and the coverage that started arriving once the successor launched was writing the case for the defense, not an obituary.

But if the actual choice in front of you is a secondary market SPB143 priced at a premium over its old $1,200 against a new SPB453 at $1,300 with a longer warranty and a receipt from an authorized dealer, buy the watch Seiko is still making. A hundred dollars separating a discontinued reference’s last known retail price from its factory fresh successor is not a gap worth paying a resale premium to avoid.

Skip this one entirely if a fixed budget matters more to you than the reference number. Chasing a specific discontinued watch through resellers is a hobby in itself, and the Citizen sitting one price tier down does the job of getting wet on a 200m rating without asking you to shop around for it.

Is the Seiko Prospex SPB143 still in production?

No. Checked directly against Seiko’s US Prospex catalogue today, the SPB143 is not listed among current divers, and Fratello covered the SPB451, SPB453 and SPB455 family as its direct successor when that line launched.

How much does the Seiko SPB143 cost now?

$1,200 where a dealer still has stock to sell, the figure Exquisite Timepieces lists today, though it shows the reference as unavailable to actually order. Secondary market listings likely run higher, but no secondary market source checked for this review was machine verifiable, so no specific used price is claimed here.

What replaced the Seiko SPB143?

The SPB451, SPB453 and SPB455, three dial colors on the same 62MAS shape, running a 6R55 movement for 72 hours of reserve and a 300m water resistance rating, against the SPB143’s 6R35, 70 hours and 200m. They launched at $1,300.

Does the SPB143 have a micro adjust clasp?

No. The bracelet’s fold over clasp has one setting, which on a rated dive watch at this price is the spec most buyers would expect and do not get here.

Is the Citizen Promaster NY0086 a real alternative to the SPB143?

For the depth rating and not much beyond it, yes. It undercuts the Seiko by roughly a thousand dollars at current retail pricing and clears a comparable water resistance category, but gives up the case finishing and about half the running time off the wrist.