Head-to-Head Comparison

Updated September 5, 2026

Junghans Form A Automatic vs Seiko Prospex "Turtle"

Junghans's dress watch meets Seiko's diver

Quick Verdict

The Seiko Prospex "Turtle" ($500–$1,000) delivers In-House Automatic Manufacture technology in the tier below the Junghans Form A Automatic ($1,000–$1,500). The Prospex "Turtle" measures 45mm and is rated 200m (20 ATM) Diver. The Form A Automatic justifies its premium with Made in Germany heritage and Automatic J800.2 (ETA 2824-2). Both represent excellent choices in the luxury watch category.

View the dossier SeikoProspex "Turtle"$500–$1,000 Check price

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Junghans

Form A Automatic

$1,000–$1,500

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Seiko

Prospex "Turtle"

$500–$1,000

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Specifications Compared

Feature	Junghans Form A Automatic	Seiko Prospex "Turtle"
Price	$1,000–$1,500	$500–$1,000
Case Size	39.3mm	45mm
Movement	Automatic J800.2 (ETA 2824-2)	Automatic Caliber 4R36
Caliber Type	Swiss ETA Base, German-Finished	In-House Automatic Manufacture
Power Reserve	38 Hours	41 Hours
Water Resistance	50m (5 ATM)	200m (20 ATM) Diver
Crystal	Flat Sapphire with Anti-Reflective Coating	Sapphire Crystal
Case Material	Stainless Steel	Stainless Steel
Origin	Made in Germany	Made in Japan

Category-by-Category Analysis

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Design & Aesthetics

Edge: Draw

Junghans's design language vs Seiko's approach

The Junghans Form A Automatic features a Stainless Steel case at 39.3mm with Flat Sapphire with Anti-Reflective Coating protection. The Seiko Prospex "Turtle" offers Stainless Steel construction at 45mm with Sapphire Crystal. Both represent their brand's distinct design philosophy and heritage.

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Movement & Performance

Edge: Seiko

Automatic J800.2 (ETA 2824-2) vs Automatic Caliber 4R36

The Form A Automatic runs the Automatic J800.2 (ETA 2824-2) (Swiss ETA Base, German-Finished, 38 Hours power reserve) at 28,800 vph (4 Hz) frequency. The Prospex "Turtle" uses the Automatic Caliber 4R36 (In-House Automatic Manufacture, 41 Hours reserve) at 21,600 vph (3 Hz). The Prospex "Turtle" offers a longer power reserve.

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Wearability & Fit

Edge: Junghans

39.3mm vs 45mm — different wrist presence

At 39.3mm, the Form A Automatic wears more compactly on smaller wrists compared to the Prospex "Turtle" at 45mm. Water resistance differs: 50m (5 ATM) vs 200m (20 ATM) Diver.

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Value & Cost of Ownership

Edge: Seiko

Seiko sits in the lower tier

The Junghans Form A Automatic sits at $1,000–$1,500 and the Seiko Prospex "Turtle" at $500–$1,000. On the specs that outlast any price: the Form A Automatic uses Flat Sapphire with Anti-Reflective Coating with 38 Hours, against Sapphire Crystal and 41 Hours on the Prospex "Turtle". Service intervals are typically 5-7 years for both.

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Water Resistance

Edge: Seiko

50m (5 ATM) vs 200m (20 ATM) Diver

The Form A Automatic is rated to 50m (5 ATM) while the Prospex "Turtle" handles 200m (20 ATM) Diver. The Prospex "Turtle" offers superior water resistance.

Our Verdict

Junghans

Form A Automatic

Choose the Junghans Form A Automatic if you prioritize Swiss ETA Base, German-Finished engineering, Made in Germany craftsmanship, and 50m (5 ATM) water resistance. At $1,000–$1,500, it delivers Automatic J800.2 (ETA 2824-2) with 38 Hours power reserve.

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Seiko

Prospex "Turtle"

Choose the Seiko Prospex "Turtle" if you value In-House Automatic Manufacture technology, Made in Japan heritage, and 45mm proportions. At $500–$1,000, the Automatic Caliber 4R36 with 41 Hours power reserve makes it a compelling choice.

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The Bottom Line

The Junghans Form A Automatic and Seiko Prospex "Turtle" represent two distinct approaches to fine watchmaking — the Junghans bringing Made in Germany tradition while Seiko delivers Made in Japan engineering.

Frequently Asked Questions

For water, the Seiko Prospex "Turtle" is rated 200 m against 50 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 $1,000–$1,500), 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 Junghans Form A Automatic may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The Form A Automatic at 39.3mm with 50m (5 ATM) water resistance handles everyday situations. The Prospex "Turtle" at 45mm with 200m (20 ATM) Diver is similarly capable. The Form A Automatic uses Flat Sapphire with Anti-Reflective Coating while the Prospex "Turtle" uses Sapphire Crystal.

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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.