Since the 1950s, the replica Blancpain Fifty Fathoms family of dive watches has played a major role in the history of professional and recreational diving. Today, Blancpain remains a staunch high-end luxury watchmaker, but it has always insisted on making serious dive watches, and no matter how luxurious or unique they may be, they are still powerful tool watches designed to provide practical service for underwater activities. To test this, I wore a solid 18k red gold Fifty Fathoms watch …