What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
The Tudor Pelagos FXD Marine Nationale 25707B is a 42 mm titanium tool watch built around fixed strap bars and a bidirectional navigation bezel. Tudor’s published specification sheet lists 200 m water resistance and an automatic, COSC-certified MT5602 movement with approximately 70 hours of power reserve. Those are manufacturer specifications—not results from independent wear, timing or water-resistance tests. One buying detail needs particular care: the older specification sheet identifies reference 25707B/21, while Tudor’s current English product page displays M25707B/26-0001, so confirm the exact generation and paperwork before purchasing.
What the Pelagos FXD Marine Nationale is designed to do
Tudor describes the Pelagos FXD as developed with French Navy combat swimmers for underwater navigation. The company’s overview says its renewed partnership with the Marine nationale was announced in 2021, renewing a relationship that began in 1956 and lasted for decades. This is Tudor’s account of the collaboration and intended use; it does not establish that a particular watch was issued to military personnel.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Tudor Pelagos FXD Automatic Chronometer Blue Dial Men's Watch m25707kn-0001 | $4,249.99 | Buy on Amazon |
| 2 |
|
TUDOR Pelagos FXD CHRONO | $4,879.99 | Buy on Amazon |
| 3 |
|
Tudor Pelagos Chronometer Black Dial Titanium Men's Watch M25600TN-0001 | $5,399.99 | Buy on Amazon |
“FXD” refers to the fixed strap bars, according to Tudor. Unlike a conventional watch with removable spring bars, this case has integrated bars that the strap passes around. That construction is central to the watch’s design, but it also affects replacement-strap choices.
Reference and generation: identify the exact watch first
Tudor’s specification sheet describes the Pelagos FXD as reference 25707B/21. The current English product page presents M25707B/26-0001. Do not assume the two designations refer to the same production generation or that every current-page detail applies to an older example. Check the reference on the watch and its documentation, and make sure the listing, warranty card and seller’s description agree. Tudor’s current product page is useful for understanding its present model presentation, but it is not a substitute for identifying the watch being offered.
Recommended Free Tools
#1 Best Overall
- Featuring a Blue Band, Black Case, Scratch Resistant Sapphire Crystal
- Display Type: Analog
- Item Shape: Round
Published specifications for reference 25707B/21
The figures below come from Tudor’s specification sheet for reference 25707B/21. They are published specifications, not measurements made for this review.
| Component | Tudor-published specification |
|---|---|
| Case | Titanium, satin-brushed; 42 mm diameter, 12.75 mm thick and 52 mm lug-to-lug; fixed strap bars; steel case back |
| Bezel | Bidirectional titanium bezel with ceramic disc and 60-minute retrograde graduation, described for navigation in successive stages |
| Dial and crystal | Navy blue dial; sapphire crystal |
| Water resistance | 200 m (660 ft), as stated by Tudor |
| Movement | Manufacture Calibre MT5602, self-winding mechanical movement with bidirectional rotor; central hours, minutes and seconds; stop-seconds |
| Certification and regulation | COSC-certified; variable-inertia balance with micro-adjustment screw and non-magnetic silicon balance spring |
| Frequency and jewels | 28,800 beats per hour (4 Hz); 25 jewels |
| Power reserve | Approximately 70 hours, as stated by Tudor |
| Straps supplied | Navy self-gripping fabric strap with grey central thread, plus navy rubber strap with woven motif and titanium buckle |
The specification sheet lists a Swiss price of CHF 3,700 including VAT. That is a historical document value, not a current price quotation. Tudor’s current English product page lists a 22 mm lug width; verify the size and strap details for the exact reference rather than assuming they carry over unchanged.
Bezel, water resistance and movement: what the numbers do—and do not—tell you
Navigation bezel
Tudor specifies a bidirectional bezel with a 60-minute retrograde graduation, intended to support navigation in successive stages. This differs from treating the bezel as a conventional elapsed-time dive bezel. The published design description does not establish how smoothly a particular example turns, whether its markings align perfectly, or how easy it is to read in use.
Rank #2
- Tudor Pelagos FXD Chronograph Cycling Automatic Black Dial Men's M25827KN-0001
Water resistance
The 200 m (660 ft) rating is Tudor’s stated specification for reference 25707B/21. It should not be read as evidence that an individual pre-owned watch remains water-tight: condition, prior service and seal integrity matter. No independent pressure test is reported here, so have a used example’s water resistance checked by a qualified watchmaker before exposing it to water.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Movement
The MT5602’s COSC certification and approximately 70-hour reserve are manufacturer-published characteristics. The specification sheet also gives a 4 Hz frequency, 25 jewels, stop-seconds and a silicon balance spring. No timing data or reserve measurement is available for an individual watch here, so these specifications cannot establish its current accuracy or service condition.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Fixed bars and strap compatibility
The original sheet says reference 25707B/21 was supplied with a navy self-gripping fabric strap and a navy rubber strap with woven motif and titanium buckle. Tudor’s current page gives a 22 mm lug width, but ordinary lug width alone does not confirm compatibility: the fixed bars change how a strap must attach and pass through the case.
Rank #3
- Tudor Pelagos Chronometer Black Dial Titanium Men's Watch M25600TN-0001
- Ask whether both original straps are included, and inspect their condition and fit on the specific watch.
- For a replacement strap, confirm explicitly that it is designed for the Pelagos FXD’s fixed bars and the exact reference. Do not rely only on a stated 22 mm width.
- Check the fastening hardware and strap wear in person or through clear seller photographs; no assessment of a particular strap’s security or comfort is established here.
What the official specifications cannot tell you about wearing it
The 42 mm diameter and 52 mm lug-to-lug measurement give useful dimensions, but they do not determine how the watch will sit on a particular wrist. The available manufacturer information does not establish firsthand comfort, perceived thickness, balance, strap feel, bezel action, lume performance, legibility, measured accuracy or durability. If those qualities matter to your decision, try the exact watch on and inspect its condition rather than treating design intent or specifications as a hands-on finding.
Buying advice: verify the listing, warranty and price
Before deciding whether an example is worth buying, compare the exact reference and condition against the asking price. Confirm the seller, included straps, service history, documentation and any water-resistance test. Tudor’s current product page describes a five-year transferable guarantee with no registration or periodic maintenance checks; verify whether that guarantee applies to the specific watch, its market and its warranty documentation instead of assuming current terms cover an older example. Tudor provides an official retailer route on its product page, but availability and regional pricing need to be checked directly.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
