Fortis b 42 marinemaster chronograph proves that the brand is capable of producing superb watches for professional divers though it is mainly known for high quality aviation timepieces it is equipped with swiss made valjoux 7750 automatic calibre that performs 28 800 vibrations per hour and has 25 bearing jewels other movement characteristics include a fine timing device and incabloc shock absorber hands numerals indices and bezel markers are covered with luminous paint that enhances night