Corum has been making watches for yachtsmen since 1960, when it debuted the first Corum Admiral’s Cup watch, named after and inspired by the famous yacht race of the same name. The Admiral’s Cup has since grown to become an entire collection, one of Corum’s core pillars. Numerous variations on the Corum Admiral’s Cup have been introduced over the years, including, at Baselworld 2014, the Corum Admiral’s Cup AC-One 45 Tides. This watch’s movement, Caliber CO 277 — which Corum spent three years working with the Astronomic Observatory of Geneva and French Navy’s oceanographic institute to create — contains a mechanical complication that is eminently useful for someone piloting a boat: a moon-phase-like function that informs the wearer of how strong and how high the tides are, and when high and low tide will next occur. (Tides, of course, are affected by the moon’s relation to the earth and sun.) A hand on the subdial at 12 o’clock indicates the tidal coefficient, or range between high and low tides. A subdial at 6 o’clock tells when the next two tides will occur. Meanwhile, the 9 o’clock display tells the wearer if tides are rising or falling. The date is displayed at 3 o’clock. The Corum Admiral’s Cup AC-One 45 Tides has the collection’s hallmark 12-sided case, which is made of titanium coated with blue PVD and measures 45 mm in diameter, and comes on a vulcanized blue rubber strap.