Seiko Turtle: the 6309-7040 vs the SRP777 and SRPE93
The original 1976 Turtle next to the modern Prospex Turtles, spec by spec.
Quick answer
The modern Turtle copies the original’s 45 mm cushion case closely, so the choice is about the watch’s age, not its size. An original 6309-7040 suits someone who wants the 1970s diver and will check it for replaced dials and hands. The SRPE93 suits someone who wants a new Turtle with 200 m water resistance and a hacking, hand-winding 4R36, at $525 from Seiko USA in October 2026. The SRP777 that started the modern line is no longer in Seiko USA’s catalog.
Side by side
| 6309-7040 / 7049 (1976) | SRP777 | SRPE93 | |
|---|---|---|---|
| Diameter and thickness | 45 mm, 13 mm | 45.0 mm, 13.4 mm | 45.0 mm, 13.4 mm |
| Lug to lug and lug width | 48 mm, 22 mm | Not listed by Seiko, 22 mm | Not listed by Seiko, 22 mm |
| Movement | 6309 automatic, 17 jewels, 21,600 vph, day and date | 4R36 automatic, 24 jewels, 21,600 vph, about 41 hours, day and date | Same 4R36 |
| Hacking and hand-winding | Neither | Both | Both |
| Water resistance | 150 m when new | 200 m | 200 m |
| Crystal | Flat Hardlex | Hardlex | Hardlex |
| Strap | GL831 rubber | Silicone | Black silicone |
| Seiko USA list price, Oct 2026 | Not applicable | No longer listed | $525 |
Original specs from Worn & Wound; modern specs from Seiko’s product pages.
How they wear
Almost the same. Both are 45 mm cushion cases with the crown at 4 and 22 mm lugs, and the modern case is only about 0.4 mm thicker by the published figures. Fratello ties the SRP777 directly to the 6309-7040 and 7049, and Worn & Wound compared the two in February 2016. Seiko’s own pages call the modern case “an iconic Seiko case design” without naming the 6309.
The bigger difference is inside: the 4R36 hacks and hand-winds, and the 6309 does neither.
The price gap
We’ll add the original’s sold range after our first sampling of eBay sales in November 2026. Seiko USA listed the SRPE93 at $525 in October 2026. The SRP777 is no longer in its catalog, so expect to find it pre-owned or as remaining dealer stock. We sample the modern Turtles separately and keep them out of the vintage range.
The case for the original
It’s the 1976 watch, and one of the easier vintage Seiko divers to own: plentiful and simple to service. The catch is how often parts have been replaced: dials, hands, crystals and bezel inserts are all available as reproductions. Read our 6309 Turtle buying checks and our 6309 movement page before you pay.
The case for the modern one
The SRPE93 is the Turtle shape as a new watch: 200 m, a movement that hacks and hand-winds, and a Seiko warranty and service network behind it. If you want a diver you’ll actually swim with, it’s the simpler choice.
Other modern Turtles
- SRPK01: the PADI Special Edition, with a sapphire crystal and a steel bracelet; 45.0 mm, 13.2 mm thick, 47.7 mm lug to lug. $650 at Seiko USA in October 2026.
- HBB002: a 2026 PADI 60th anniversary limited edition of 8,000, with sapphire, a bracelet and a spare silicone strap. $750 at Seiko USA in October 2026.
Where to look
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FAQ
Is the Seiko SRP777 discontinued?
It's no longer in Seiko USA's catalog; its product page returned a 404 when we checked on October 27, 2026. The SRPE93 has the same 45 mm case and 4R36 movement and is still listed.
What is the modern equivalent of the Seiko 6309?
The Prospex Turtle, such as the SRPE93. It keeps the 45 mm cushion case and 22 mm lugs but uses the 4R36 movement, which hacks and hand-winds, and is rated to 200 m instead of 150 m.
Is the modern Seiko Turtle the same size as the 6309?
Close. Both are 45 mm wide with 22 mm lugs. Worn & Wound gives the 6309 as 13 mm thick; Seiko gives the SRP777 and SRPE93 as 13.4 mm.
Who should choose a vintage 6309 over a new Turtle?
Someone who wants the original and is ready to check it for replaced parts and pay for a service. If you want a diver to swim with and no surprises, the new Turtle is the simpler watch.