Name: Tudor Black Bay 41 M79230N
Brand: Tudor
SKU: M79230N

The Black Bay 41 is the Tudor most buyers end up with, and for good reason. Correct dive watch proportions, in-house movement, 200m water resistance, and a price that leaves room in the budget for a strap collection. If the Submariner is the benchmark, the BB41 is the honest answer.

What it is

Tudor relaunched the Black Bay in 2012 as a direct nod to its own dive watch heritage from the 1950s and 1960s, drawing on the broad crown-guards and domed crystal of those original references. The 41mm case arrived in 2017, settling the size debate that had followed the original 41mm launch and replacing the ETA movement with Tudor's own MT5602. The MT5602 shares its base architecture with Rolex's caliber 3135 and carries a 70-hour power reserve, which is serious engineering for the price point.

Snowflake and dagger hand variants have coexisted across the lineup, giving buyers a meaningful choice without fragmenting the core reference. The M79230N is the steel case on leather or fabric strap, the purist configuration before you get into bracelet or bronze territory.

Buying notes

The BB41 market is liquid enough that pre-owned prices cluster tightly, so paying full retail is rarely necessary. Watch the dial condition carefully on older examples: the applied Tudor rose logo can show wear at the base where it meets the dial, which is cosmetic but worth negotiating on. Bracelets on earlier production runs had noticeable play at the clasp; if the watch comes on a bracelet, check that before buying.

Some buyers find the domed crystal scratches more readily than a flat sapphire, so ask about the crystal condition specifically. Tudor's warranty transfers with proof of purchase, but the secondary market frequently moves watches without paperwork, so price accordingly if box and papers are absent.

Market read

Pre-owned M79230N examples in good condition trade in the $2,800 to $3,500 range depending on configuration and completeness. Full set with box and papers commands a modest premium. The spread between the BB41 and a comparable pre-owned Submariner is roughly $4,000 to $6,000, which is the core of the value argument for Tudor buyers.

Service expectations

The MT5602 is a COSC-certified in-house caliber with a 70-hour power reserve and Tudor recommends service intervals of approximately ten years under normal wear. Tudor's authorized service network services the MT5602 directly, and pricing is substantially below what Rolex charges for a comparable movement service. Keep records of any service performed, as documentation adds to resale value on a watch that trades frequently in the pre-owned market.

Editorial copy is AI-drafted from primary sources and reviewed by Grail Atlas before publication. Where the text is uncertain about a fact, it says so. Email corrections@grailatlas.com if something reads wrong. Signals on this page (community, OSINT) are clearly separated from the editorial sections.

Mass-produced#3 in family

Condition affects price

Pre-owned watches trade across a wide condition spectrum. These ranges are typical for the secondary market.

New Old Stock

Unworn example retaining original packaging, tags, and warranty documentation.

+30–50% vs median

Unpolished

Worn but the case has never been polished; original brushed and polished surfaces are intact.

+15–25% vs median

Polished

Case has been professionally or amateur polished at some point; edge definition is softened.

-15 to -5% vs median

Recently Serviced

Movement has been recently serviced with documented service records; case condition varies.

At median

Project

Needs service, has dial or hand issues, non-original parts, or other remediation before daily wear.

-50 to -25% vs median

Full condition grading guide →

Market price

$2,000–$2,900

steel·2026 Q2

Price trend chart coming soon

The 41mm Black Bay is the value entry point into Tudor sport watches and trades close to retail; strong brand support and wide availability keep the secondary market liquid.

Editorial estimate, 2026 Q2. Actual prices vary by condition, date, and box/papers status.

Movement tier: unclassified · caliber Tudor MT5602: in-house automatic, 28,800bph, 70h PR, 26j; COSC-certified, bidirectional winding; used in Black Bay 41 and Pelagos FXD · 70h power reserve (2.9 days)

Medium-large: suits wrists 6.5 in+ (16.5 cm+)

41 mm case. Wears confidently on average to larger wrists. May overhang on slender builds.

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Authentication

The GMT hand must advance in one-hour increments independently; a GMT hand linked to the main hour hand means the GMT complication has failed.

Known issues in the market

GMT hand failure results in the hand tracking the main hour hand rather than advancing independently; test GMT function before purchase.
Cal. MT5602 is shared with the Pelagos FXD; all METAS certification and service notes apply identically.
The 41mm Black Bay uses the same Snowflake or Mercedes handset options as the 39mm; verify handset matches the reference number.

Area	What to check	What is correct	Red flag
dial	GMT hand independent advancement	Red GMT arrow hand advances one hour at a time via crown; main hour hand unaffected	GMT hand that moves simultaneously with the main hour hand indicating GMT complication failure
caseback	Cal. MT5602 in-house movement	Tudor Cal. MT5602 visible and signed through caseback; METAS-certified movement	Non-Tudor movement visible indicating a movement swap
case	Bezel external GMT function	External bezel rotates to track a second timezone; 24-hour graduated scale is correct for GMT use	12-hour graduated bezel scale instead of 24-hour indicating a wrong-specification bezel swap

Common legitimate replacements

Cal. MT5602 GMT complication service requires Tudor or authorized center access; independent parts are not available.
The 24-hour external bezel is specific to the GMT configuration; a 60-minute dive bezel is the wrong specification for this reference.

Expert resources: Tudor Black Bay 41 documentation at tudorwatch.com. WatchUSeek Tudor subforum for GMT function testing and Cal. MT5602 service history.

Authentication guide

Last reviewed June 2026

The Black Bay 41 is the standard steel dive watch in the Black Bay line. At 41mm and 14.8mm thick it is noticeably larger and thicker than the BB58. The MT5602 inside is the same caliber as the Black Bay GMT. Authentication is straightforward for this reference: snowflake hand proportions and the MT5602 movement verification are the primary checks.

Known reproduction risks

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MEDIUM

Replicas of the Black Bay line using ETA or Sellita movements with snowflake hand approximations.

Snowflake hand proportions off -- the most immediate visual check
Date window absent on a stated BB41
Caseback without Tudor manufacture designation
Crown at position 1 advancing a GMT hand on a stated BB41 (the BB41 has no GMT)

Dial variants by era

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Era	Description	Identifiers
2017 to present (black)	Black dial with snowflake hands and applied dot indices. The BB41 has a date window at 3 o'clock, unlike the no-date BB58.	Black dial with applied dot indices (not Arabic numerals) Date window at 3 o'clock -- the BB41 is a date model; the BB58 is no-date Snowflake hands scaled to the 41mm case -- wider and longer than the BB58 hands Unidirectional rotating bezel with an aluminum insert 41mm x 14.8mm case -- thicker and larger diameter than the BB58 (39mm x 11.9mm)
2017 to present (blue)	Blue dial variant. Same case, movement, and bezel system as the black dial.	Blue dial with dot indices consistent with the BB41 design language Blue bezel insert matching the dial color on some configurations

Service part flags

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MT5602 movement

Original: Tudor MT5602 is an in-house automatic, 28,800bph, 70-hour power reserve. METAS-certified. The same movement platform as the Black Bay GMT but without the GMT complication. No independent GMT hand.

Replacement tells

Crown at position 1 advancing a separate GMT hand -- the BB41 has no GMT function
Power reserve depleting in under 48 hours from full wind
Caseback without Tudor manufacture hallmarks

Date window at 3 o'clock

Original: The BB41 has a date complication. A date window at 3 o'clock is standard. The absence of a date window indicates either a BB58 (no-date) or a non-matching dial.

Replacement tells

No date window on a stated BB41 -- the 41 is a date model; absence of the date indicates a different reference or a dial swap
Date window at a position other than 3 o'clock

Case back markings

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2017 to present

Solid caseback with Tudor shield at center
"TUDOR BLACK BAY 41" on the outer ring
"MANUFACTURE MOVEMENT" and METAS reference
"200M / 660FT" water resistance rating
Reference M79230N and serial number on the case

Movement tells

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MT5602, 28,800bph, 70-hour power reserve. Same caliber as the Black Bay GMT without the GMT function. Fully wound watch should run 65 to 70 hours.
METAS-certified for rate accuracy across multiple positions.
Silicon hairspring: not affected by magnetic fields.

Sources: Tudor -- Black Bay 41 specification.