When Seiko came out with its 62MAS, Japanese watchmaking hadn’t yet seen a dive watch before. Since then, the brand continues to set the standard while evolving their range. Earlier this year, they made some crucial updates to the Prospex Diver with a new movement and improved water resistance to 300m (for steel case versions).
Closing out the 60th-anniversary celebration for their first dive watch, Seiko is offering up a limited-edition 1965 Heritage model with a stunning ocean-blue dial, and we’re wondering why more people aren’t talking about it.
Tranquil Teal Takes Center Stage
The SPB545 draws its design inspiration from Okinawa’s diving waters, which have earned their reputation as some of the clearest on the planet. That translucent quality finds its way onto the dial through what Seiko calls “Tranquil Teal” — a sunray-patterned blue that shifts between shallow turquoise and deeper ocean tones depending on the light. Paired with a matte gray bezel, the color combination is arguably the finest we’ve seen on the dive watch.
The dial layout stays true to the 1965 Heritage blueprint, featuring applied indices with LumiBrite fill, a date window at 4:30 (it’s round, it’s white, and you either vibe with it or you don’t), and the “Automatic 3 Days” inscription sitting proudly above the six o’clock marker. It’s a cleaner aesthetic than some of Seiko’s busier dials, and it’s housed in a 40mm super-hard-coated stainless steel case.
Save the Ocean, Evolved
This release continues Seiko’s Save the Ocean initiative, which kicked off back in 2018 with gradient blue dials inspired by humpback whales. The program directs proceeds toward marine conservation efforts — partnerships with organizations like PADI Aware and Fabien Cousteau’s Ocean Learning Center. Seiko’s been putting dive watches on the wrists of actual ocean explorers since the Japanese Antarctic Research Expedition in the 1960s, so there’s lineage here.
The Tech That Matters
Under the hood sits the in-house Caliber 6R55, an evolution of the 6R35 that bumps power reserve to 72 hours and runs at 21,600 vph with 24 jewels and the standard +25/-15 seconds per day accuracy.
The real upgrade here is Seiko’s new micro-adjustable clasp, which gives you six on-the-fly adjustments of 2.5mm each for a total of 15mm, which is perfect for the needs of a serious diver wearing a wetsuit or experiencing expansion in the heat.
Spec Sheet
Model: Seiko Prospex 1965 Heritage Diver’s Watch Save the Ocean Limited Edition (SPB545)
Case Material: Super-hard coated stainless steel
Case Size: 40mm
Case Thickness: 13mm
Lug-to-Lug: 46.4mm
Movement: In-house Caliber 6R55 automatic with manual winding
Power Reserve: 72 hours
Water Resistance: 300m
Crystal: Curved sapphire with anti-reflective coating on inner surface
Bracelet: Stainless steel
Limited Edition: 4,000 pieces worldwide
Pricing & Availability
Limited to 4,000 pieces, the 1965 Prospex Diver SPB545 will drop in January 2026 for $1,400, which positions it just $100 above the standard Heritage Diver models.
Recap
Seiko 1965 Prospex Diver Save the Ocean Heritage Limited Edition SPB545
Seiko’s wrapping up its 60th dive watch anniversary with the SPB545, a limited-edition 1965 Heritage model featuring a killer ocean-blue dial inspired by Okinawa’s waters and an upgraded micro-adjustable clasp.
