Seiko 6F24 Tidal Chronometer
The table cloth for is a perfect thematic Background
for this Tidal Chronometer. Both crowns have quite high crown guards. This has a reason, especially for the crown at 9 o'clock, because that crown is turning quite lightly and used to turn the inner date bezel. Interestingly that crown is purely mechanical and in now way connected to the movement. The crown at 3 o'clock is a screw-down type.