About this watch

Reference 5054-3640-76S is the Fifty Fathoms Bathyscaphe carrying a complete calendar and a moon phase, in red gold on a matching bracelet. Putting a calendar of this kind inside a dive watch is an odd thing to do, and it is the reason this one is interesting rather than merely expensive. A complete calendar is not a perpetual and not an annual. It shows the day and the month in twin apertures under twelve, the date on a pointer hand running to a ring around the dial edge, and the moon in a window at six — but it counts every month as thirty-one days, so it needs correcting five times a year. The compensation is legibility: everything is on one plane, read at a glance, with none of the recessed sub-dials a perpetual forces on the layout. The awkward part is the correctors. A calendar normally needs pushers set into the caseband, and pushers are holes. Keeping a watch sealed to thirty bar while giving it that many correction points is the engineering problem the Bathyscaphe case had to solve, and the flatter, quieter Bathyscaphe profile absorbs it better than the full Fifty Fathoms would have. From the watch itself: an 18 ct gold case, marked thirty bar on the back, over a movement…