Reference pages
Seiko Prospex Samurai SRPF03
The angular one. Slimmer than a Turtle, date only, and the sharpest case geometry Seiko sells at this price.
By Stephen V. · Updated Jul 24, 2026
The SRPF03 is a 43.8 mm Prospex diver with a 47 mm lug-to-lug, 12.8 mm thickness and 22 mm lugs, running the 4R35 automatic — date only, no day. It is rated 200 m with the ISO 6425 DIVER’S marking, a screw-down crown and a Hardlex crystal.
Samurai versus Turtle
These are the two Seiko divers people cross-shop, and the choice is mostly about case geometry rather than capability.
| Samurai SRPF03 | Turtle SRPE93 | |
|---|---|---|
| Case diameter | 43.8 mm | 45.0 mm |
| Lug-to-lug | 47.0 mm | 47.7 mm |
| Thickness | 12.8 mm | 13.2 mm |
| Movement | 4R35 (date) | 4R36 (day-date) |
| Case style | Faceted, angular | Cushion, rounded |
| Rating | 200 m ISO 6425 | 200 m ISO 6425 |
| Lug width | 22 mm | 22 mm |
The Samurai is slimmer by 0.4 mm and slightly shorter across the wrist. Its faceted case catches light in a way the Turtle’s rounded one does not, which is genuinely the main reason to choose it.
The trade is the complication: the 4R35is date-only, where the Turtle’s 4R36 has day and date. If you read the day, that decides it.
The case is the point
The Samurai’s lugs and case flanks are cut with hard, flat facets rather than the continuous curves of the Turtle. In practice that means it reflects light in distinct planes and reads as a more modern, angular object.
It also means the lug edges are sharper against the wrist. On a small or bony wrist that is noticeable, and the Turtle’s curves are more forgiving.
Living with it
Same ISO caveats as any diver
Screw the crown down. Get the gaskets checked if the watch actually goes in water. The rating is a property of the case as a system, not of the case forever.
Hardlex again
No Samurai reference in this price band ships sapphire. If the crystal matters, the King Turtle or an Orient Kamasu are the alternatives.
22 mm lugs
Shared with the Turtle and the 5KX family, so the strap options are the same and are the deepest available — see the strap roundup.
The watches on this page
Specifications are transcribed from Seiko’s published documentation. Prices come from Amazon and carry the date they were verified. We have not handled these watches — here is what we did instead.
$525.0016% off
Price as of Jul 24, 2026. Prices move — Amazon's is the one that counts.
#ad · we may earn a commission from this link to Seiko Prospex Samurai SRPF03
Seiko Prospex Samurai SRPF03
SRPF03K1Best for: A 200 m diver with sharp, faceted case geometry
The angular one. A 200 m ISO diver with hard-cut case facets — the Seiko diver you buy when the Turtle is too round.
- Spec completeness for the price
- 8.8
- Movement relative to bracket
- 8.4
- Case proportions
- 8.6
- Strap flexibility
- 9.5
- Availability
- 8.3
What it gets right
- Slimmer than the Turtle at 12.8 mm
- Faceted case catches light in a way the rounder Seikos do not
- Full ISO 6425 diver rating
What it gets wrong
- Date only — no day, unlike the 4R36 references
- Hardlex
- Sharp lug edges are less forgiving on a small wrist
Skip this one if: you want the day complication. The Samurai runs the 4R35, which is the same movement as the 4R36 minus the day wheel.
| Case diameter | 43.8 mm |
|---|---|
| Lug-to-lug | 47.0 mm |
| Thickness | 12.8 mm |
| Lug width | 22 mm |
| Crystal | Hardlex (hardened mineral) |
| Water resistance | 200 m, ISO 6425 rated |
| Crown | Screw-down |
| Caliber | Seiko 4R35 |
| Type | Automatic, hand-winding and hacking |
| Beat rate | 21,600 vph (6 beats/sec) |
| Jewels | 23 |
| Power reserve | Approx. 41 hours |
| Stated accuracy | -35 to +45 sec/day |
| Complications | Date |
$575.0020% off
Price as of Jul 24, 2026. Prices move — Amazon's is the one that counts.
#ad · we may earn a commission from this link to Seiko Prospex Samurai SRPL15
Seiko Prospex Samurai SRPL15
SRPL15K1Best for: A current-catalog Samurai with full warranty
A current-production Samurai. Same 200 m case and 4R35 as the SRPF03, with a newer dial and bracelet.
- Spec completeness for the price
- 8.5
- Movement relative to bracket
- 8.4
- Case proportions
- 8.6
- Strap flexibility
- 9.5
- Availability
- 8.6
What it gets right
- Current production
- 200 m ISO diver
- 22 mm lugs
What it gets wrong
- Hardlex
- Date only
- No functional gain over the older Samurai references
Skip this one if: an older Samurai reference is cheaper. The case, crystal and movement are the same parts.
| Case diameter | 43.8 mm |
|---|---|
| Lug-to-lug | 47.0 mm |
| Thickness | 12.8 mm |
| Lug width | 22 mm |
| Crystal | Hardlex (hardened mineral) |
| Water resistance | 200 m, ISO 6425 rated |
| Caliber | Seiko 4R35 |
| Type | Automatic, hand-winding and hacking |
| Beat rate | 21,600 vph (6 beats/sec) |
| Jewels | 23 |
| Power reserve | Approx. 41 hours |
| Stated accuracy | -35 to +45 sec/day |
| Complications | Date |
Price as of Jul 24, 2026. Prices move — Amazon's is the one that counts.
#ad · we may earn a commission from this link to Seiko Prospex Turtle SRPE93
Seiko Prospex Turtle SRPE93
SRPE93K1Best for: An actual dive watch you can also wear daily
A real 200 m ISO-rated diver with a screw-down crown, in the cushion case that wears far smaller than its 45 mm suggests.
- Spec completeness for the price
- 9.0
- Movement relative to bracket
- 8.5
- Case proportions
- 8.8
- Strap flexibility
- 9.5
- Availability
- 8.6
What it gets right
- Genuine ISO 6425 diver, not a diver-styled sports watch
- 47.7 mm lug-to-lug means it fits wrists that 45 mm suggests it should not
- Screw-down crown at 4 o'clock keeps it off the back of your hand
What it gets wrong
- Hardlex on a watch at this price is the recurring Seiko complaint
- The 45 mm figure scares people off before they try one
- Bracelet is adequate, not good
Skip this one if: you have a wrist under about 6.5 inches. The lug-to-lug is forgiving but the case is still visually wide, and the smaller SRPG references exist for exactly this reason.
| Case diameter | 45.0 mm (cushion case) |
|---|---|
| Lug-to-lug | 47.7 mm |
| Thickness | 13.2 mm |
| Lug width | 22 mm |
| Crystal | Hardlex (hardened mineral) |
| Water resistance | 200 m, ISO 6425 rated for scuba diving |
| Crown | Screw-down, at 4 o'clock |
| Bezel | Unidirectional, 120-click, lumed pip |
| Caliber | Seiko 4R36 |
| Type | Automatic, hand-winding and hacking |
| Beat rate | 21,600 vph (6 beats/sec) |
| Jewels | 24 |
| Power reserve | Approx. 41 hours |
| Stated accuracy | -35 to +45 sec/day |
| Complications | Day and date |
Questions
Is the Seiko Samurai better than the Turtle?
Neither is better. The Samurai is 0.4 mm slimmer with a faceted case and date only; the Turtle is rounder, more forgiving on a small wrist, and has day-date. Both are 200 m ISO 6425 divers with the same lug width.
What size is the Seiko Samurai?
43.8 mm diameter, 47 mm lug-to-lug, 12.8 mm thick, 22 mm lug width. The 47 mm lug-to-lug is what determines fit.
Does the Seiko Samurai have a day complication?
No — it runs the 4R35, which is date only. The 4R36 in the Turtle adds the day wheel and is otherwise identical.
Is the Samurai comfortable on a small wrist?
Less so than the Turtle. The faceted case has sharper lug edges where the Turtle’s cushion shape curves away, and that is more noticeable on a narrow or bony wrist despite the Samurai being slightly smaller on paper.
Sources
- Seiko Prospex collection — official specifications
- ISO 6425 — Horology, divers' watches (standard listing)
- Seiko Watch Corporation — US catalog and specifications
Specifications are transcribed from manufacturer documentation and published standards. Where a manufacturer does not publish a figure, this page says so rather than estimating one.