Head-to-Head Comparison

Updated September 5, 2026

Mido Ocean Star GMT vs Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet)

Two divers compared — $1,000–$1,500 vs $2,500–$5,000

Quick Verdict

The Mido Ocean Star GMT ($1,000–$1,500) offers Automatic (ETA C07.661 base) precision in the tier below the Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) ($2,500–$5,000). The Ocean Star GMT measures 44mm and is rated 200m (20 ATM). The Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) counters with Swiss Made craftsmanship and 200m (20 ATM) water resistance. Both are exceptional divers for their respective tiers.

MidoOcean Star GMT$1,000–$1,500 Check price TudorBlack Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet)$2,500–$5,000 Check price

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Mido

Ocean Star GMT

$1,000–$1,500

Check Price Full Review

Tudor

Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet)

$2,500–$5,000

Check Price Full Review

Specifications Compared

Feature	Mido Ocean Star GMT	Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet)
Price	$1,000–$1,500	$2,500–$5,000
Case Size	44mm	39mm, 14.6mm thick, 20mm lugs
Movement	Automatic Caliber 80 (Base ETA C07.661)	Tudor manufacture calibre MT5652, automatic GMT with independently adjustable hour hand, COSC chronometer, bidirectional rotor
Caliber Type	Automatic (ETA C07.661 base)	Tudor manufacture MT5652, COSC
Power Reserve	80 Hours	About 70 hours
Water Resistance	200m (20 ATM)	200m (20 ATM)
Crystal	Sapphire with Double-sided AR	Domed sapphire
Case Material	Stainless Steel	Stainless steel, polished and satin; fixed 24-hour graduated bezel in satin-brushed steel; screw-down crown
Origin	Swiss Made	Swiss Made

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Mido's design language vs Tudor's approach

The Mido Ocean Star GMT features a Stainless Steel case at 44mm with Sapphire with Double-sided AR protection. The Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) offers Stainless steel, polished and satin; fixed 24-hour graduated bezel in satin-brushed steel; screw-down crown construction at 39mm, 14.6mm thick, 20mm lugs with Domed sapphire. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Mido

Automatic Caliber 80 (Base ETA C07.661) vs Tudor manufacture calibre MT5652, automatic GMT with independently adjustable hour hand, COSC chronometer, bidirectional rotor

The Ocean Star GMT runs the Automatic Caliber 80 (Base ETA C07.661) (Automatic (ETA C07.661 base), 80 Hours power reserve) at 21,600 vph (3 Hz) frequency. The Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) uses the Tudor manufacture calibre MT5652, automatic GMT with independently adjustable hour hand, COSC chronometer, bidirectional rotor (Tudor manufacture MT5652, COSC, About 70 hours reserve) at standard. The Ocean Star GMT edges ahead on power reserve.

📏

Wearability & Fit

Edge: Tudor

44mm vs 39mm, 14.6mm thick, 20mm lugs — different wrist presence

At 44mm, the Ocean Star GMT has a bolder wrist presence compared to the Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) at 39mm, 14.6mm thick, 20mm lugs. Water resistance differs: 200m (20 ATM) vs 200m (20 ATM).

💰

Value & Cost of Ownership

Edge: Mido

Mido sits in the lower tier

The Mido Ocean Star GMT sits at $1,000–$1,500 and the Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) at $2,500–$5,000. On the specs that outlast any price: the Ocean Star GMT uses Sapphire with Double-sided AR with 80 Hours, against Domed sapphire and About 70 hours on the Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet). Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Draw

200m (20 ATM) vs 200m (20 ATM)

The Ocean Star GMT is rated to 200m (20 ATM) while the Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) handles 200m (20 ATM). Both offer identical water resistance ratings.

Our Verdict

Mido

Ocean Star GMT

Choose the Mido Ocean Star GMT if you prioritize Automatic (ETA C07.661 base) engineering, Swiss Made craftsmanship, and 200m (20 ATM) water resistance. At $1,000–$1,500, it delivers Automatic Caliber 80 (Base ETA C07.661) with 80 Hours power reserve.

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Tudor

Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet)

Choose the Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) if you value Tudor manufacture MT5652, COSC technology, Swiss Made heritage, and 39mm, 14.6mm thick, 20mm lugs proportions. At $2,500–$5,000, the Tudor manufacture calibre MT5652, automatic GMT with independently adjustable hour hand, COSC chronometer, bidirectional rotor with About 70 hours power reserve makes it a compelling choice.

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The Bottom Line

The Mido Ocean Star GMT and Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) represent two distinct approaches to the diver category — the Mido bringing Swiss Made tradition while Tudor delivers Swiss Made engineering.

Frequently Asked Questions

On price, the Mido Ocean Star GMT sits a band lower ($1,000–$1,500 against $2,500–$5,000), 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 Mido Ocean Star GMT offers better upfront value, sitting a tier lower at $1,000–$1,500. However, the Tudor Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The Ocean Star GMT at 44mm with 200m (20 ATM) water resistance handles everyday situations. The Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) at 39mm, 14.6mm thick, 20mm lugs with 200m (20 ATM) is similarly capable. The Ocean Star GMT uses Sapphire with Double-sided AR while the Black Bay Pro 39mm M79470-0001 (steel, fixed 24-hour bezel, black dial, riveted steel bracelet) uses Domed sapphire.

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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.