c'est un 8L35 et pas le 6r15 dans la marinemaster...
"The movement is an 8L35, an undecorated and unadjusted version of the high-end Grand Seiko 9S55. Rhodium-plated, 26 jewels, automatic, 28800vph (4Hz), handwind and hacking, 50 hour power reserve. Anecdotally, the size of the balance wheel was increased to provide the torque required, as the hands are heavier than a dress watch. The 8L35 is also used in the Landmaster, which has the same hands.
The movement by all accounts keeps excellent time, and in 9S55 trim is capable of exceeding COSC specs. Anecdotal reports on various fora indicate less than five seconds’ daily error is typical. The spec is -10 to +15 seconds per day.
The 8L35 is completely in-house Seiko, and is descended from the 6159 300m diver, circa 1969. Everything from oil on up, including mainspring, is Seiko. Kinda cool. What they call a ‘manufacture’."
Et une revue sympa:
http://66.102.9.104/search?q=cache:9NXO5SU_qioJ:www.phfactor.net/wp/2006/12/26/the-seiko-marinemaster-page/+8l35&hl=fr&ct=clnk&cd=15&gl=fr&client=firefox-a
Accueil 
Comme le battement du calibre, ce qui explique en partie cette fluidité. 
