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Fortis · Marinemaster

Fortis Marinemaster M-40

Reference F8120024 · Dive · 40 mm

14Ø 40 mmLug-to-lug 43 mm
Illustration drawn from the specifications: case to scale, colours and style approximate. Not a photo. Photos on the official page

Specifications

Reference
F8120024
Family
Marinemaster
Category
Dive
Status
Current
Case material
Stainless steel
Case diameter
40 mm
Case thickness
12 mm Official
Lug-to-lug
43 mm Official
Lug width
—
Water resistance
300 m
Bezel
—
Calibre
UW-30 Official
Power reserve
38 h

Official product page · retrieved October 25, 2026

Does it fit your wrist?

Enter your wrist circumference. The watch appears to scale on the flat top of the wrist.

14Lug-to-lug 43 mmFlat top of the wrist 54.1 mm
Top view on a wrist, to scale
Flat top of the wrist 54.1 mmLug-to-lug 43 mmCase diameter 40 mm
Side view, across the wrist

Comfortable

Lug-to-lug 43 mm on a flat top of 54.1 mm: 80 % of the width.

Lug-to-lug is 75 to 95% of the flat top, the usual comfortable range.

Measurements and sources

Brands rarely publish thickness, lug width and lug-to-lug together. Each observation below is kept separate, with who gave it.

Case thickness

Value Type Source Date
12 mm Official Fortis October 25, 2026

Lug-to-lug

Value Type Source Date
43 mm Official Fortis October 25, 2026

Lug width

Lug width is the gap between the lugs, where the strap fits. It is not lug-to-lug.

No source gave this figure yet.

Calibre source

Official Fortis · retrieved October 25, 2026

Other versions in the same case

These references differ only by dial, bracelet or bezel colour. The brand gives them the same case dimensions, so the figures on this page apply to them too.

  • F8120012 · Blue Japan / Block Bracelet
  • F8120026 · Gravity Black / Horizon Strap
  • F8120028 · Ocean Blue / Horizon Strap
  • F8120005 · Rockstone Gray / Horizon Strap
  • F8120003 · Serenity Blue / Horizon Strap
  • F8120009 · Snow White / Horizon Strap
  • F8120007 · Woodpecker Green / Horizon Strap

Other Marinemaster references

Watch Ø Thickness Lug-to-lug Calibre
Marinemaster M-44 F8120013 44 mm 14 mm 48 mm Werk 11

Other Fortis models

Watch Ø Thickness Lug-to-lug Calibre
Vagabond V-40 F6660000 40 mm 13.9 mm 46.5 mm Werk 13
Flieger F-39 F4220005 39 mm 12.5 mm 50 mm UW-30
Flieger F-39 Werk 7 F4220028 39 mm 12.5 mm 50 mm Werk 7
Flieger F-41 F4220008 41 mm 12.5 mm 52 mm UW-30
Flieger F-41 Werk 7 F4220030 41 mm 12.5 mm 52 mm Werk 7
Flieger F-43 Triple-GMT F4260000 43 mm 15.5 mm 54 mm Werk 13
Show 4 more
Watch Ø Thickness Lug-to-lug Calibre
Stratoliner S-41 F2340006 41 mm 14.5 mm 50.5 mm Werk 17
Novonaut N-42 F2040008 42 mm 15 mm 51 mm Werk 17
Novonaut N-42 TR F2040021 42 mm 15 mm 51 mm Werk 17 TR
Flieger F-43 Bicompax F4240004 43 mm 15.5 mm 54 mm UW-51

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