Head-to-Head Comparison

Updated September 5, 2026

Seiko Prospex "Turtle" vs Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet)

Two divers compared — $500–$1,000 vs $5,000–$10,000

Quick Verdict

The Seiko Prospex "Turtle" ($500–$1,000) offers In-House Automatic Manufacture precision in the tier below the Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) ($5,000–$10,000). The Prospex "Turtle" measures 45mm and is rated 200m (20 ATM) Diver. The Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) counters with Swiss Made craftsmanship and 500m (50 ATM) water resistance. Both are exceptional divers for their respective tiers.

SeikoProspex "Turtle"$500–$1,000 Check price TudorPelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet)$5,000–$10,000 Check price

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Seiko

Prospex "Turtle"

$500–$1,000

Check Price Full Review

Tudor

Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet)

$5,000–$10,000

Check Price Full Review

Specifications Compared

Feature	Seiko Prospex "Turtle"	Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet)
Price	$500–$1,000	$5,000–$10,000
Case Size	45mm	42mm, 14.3mm thick, 22mm lugs
Movement	Automatic Caliber 4R36	Tudor manufacture calibre MT5612, automatic, COSC chronometer, bidirectional rotor
Caliber Type	In-House Automatic Manufacture	Tudor manufacture MT5612, COSC
Power Reserve	41 Hours	About 70 hours
Water Resistance	200m (20 ATM) Diver	500m (50 ATM)
Crystal	Sapphire Crystal	Sapphire Crystal
Case Material	Stainless Steel	Titanium with steel caseback, satin finish; unidirectional titanium bezel with matt blue ceramic disc and luminous graduations; helium escape valve at 9; titanium screw-down crown
Origin	Made in Japan	Swiss Made

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Seiko's design language vs Tudor's approach

The Seiko Prospex "Turtle" features a Stainless Steel case at 45mm with Sapphire Crystal protection. The Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) offers Titanium with steel caseback, satin finish; unidirectional titanium bezel with matt blue ceramic disc and luminous graduations; helium escape valve at 9; titanium screw-down crown construction at 42mm, 14.3mm thick, 22mm lugs with Sapphire Crystal. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Tudor

Automatic Caliber 4R36 vs Tudor manufacture calibre MT5612, automatic, COSC chronometer, bidirectional rotor

The Prospex "Turtle" runs the Automatic Caliber 4R36 (In-House Automatic Manufacture, 41 Hours power reserve) at 21,600 vph (3 Hz) frequency. The Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) uses the Tudor manufacture calibre MT5612, automatic, COSC chronometer, bidirectional rotor (Tudor manufacture MT5612, COSC, About 70 hours reserve) at standard. The Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) offers a longer power reserve.

📏

Wearability & Fit

Edge: Tudor

45mm vs 42mm, 14.3mm thick, 22mm lugs — different wrist presence

At 45mm, the Prospex "Turtle" has a bolder wrist presence compared to the Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) at 42mm, 14.3mm thick, 22mm lugs. Water resistance differs: 200m (20 ATM) Diver vs 500m (50 ATM).

💰

Value & Cost of Ownership

Edge: Seiko

Seiko sits in the lower tier

The Seiko Prospex "Turtle" sits at $500–$1,000 and the Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) at $5,000–$10,000. On the specs that outlast any price: the Prospex "Turtle" uses Sapphire Crystal with 41 Hours, against Sapphire Crystal and About 70 hours on the Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet). Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Tudor

200m (20 ATM) Diver vs 500m (50 ATM)

The Prospex "Turtle" is rated to 200m (20 ATM) Diver while the Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) handles 500m (50 ATM). The Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) offers superior water resistance.

Our Verdict

Seiko

Prospex "Turtle"

Choose the Seiko Prospex "Turtle" if you prioritize In-House Automatic Manufacture engineering, Made in Japan craftsmanship, and 200m (20 ATM) Diver water resistance. At $500–$1,000, it delivers Automatic Caliber 4R36 with 41 Hours power reserve.

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Tudor

Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet)

Choose the Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) if you value Tudor manufacture MT5612, COSC technology, Swiss Made heritage, and 42mm, 14.3mm thick, 22mm lugs proportions. At $5,000–$10,000, the Tudor manufacture calibre MT5612, automatic, COSC chronometer, bidirectional rotor with About 70 hours power reserve makes it a compelling choice.

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The Bottom Line

The Seiko Prospex "Turtle" and Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) represent two distinct approaches to the diver category — the Seiko bringing Made in Japan tradition while Tudor delivers Swiss Made engineering.

Frequently Asked Questions

For water, the Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) is rated 500 m against 200 m, which is the difference between swimming and diving on one side and splashes on the other. On price, the Seiko Prospex "Turtle" sits a band lower ($500–$1,000 against $5,000–$10,000), so it is the cheaper way into the category. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.

The Seiko Prospex "Turtle" offers better upfront value, sitting a tier lower at $500–$1,000. However, the Tudor Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The Prospex "Turtle" at 45mm with 200m (20 ATM) Diver water resistance handles everyday situations. The Pelagos 42mm M25600TB-0001 (titanium, blue ceramic bezel, blue dial, titanium bracelet) at 42mm, 14.3mm thick, 22mm lugs with 500m (50 ATM) is similarly capable. Both use Sapphire Crystal, which resists scratches well.

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How This Page Was Made

Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.