Corum’s Admiral’s Cup Tides watch made waves in the luxury watch market when it was launched in 1993, and it remains the only watchmaking complication of its kind on the market. In addition to telling the time of day, the self-winding Admiral Cup Tides is an essential instrument for those who sail in tidal waters, showing the times of high and low water, the state of the tide, the strength of the tidal current and the tidal range.
The three different mechanisms for the tidal indications were designed with the help of the Geneva Observatory and the French Navy’s hydrographic and oceanographic service (SHOM) in Brest. Their development took three years from 1988 to 1991.
The Corum tidal movement, Caliber CO277, has a power reserve of 42 hours and its exactitude has been certified by the SHOM. This movement is fitted only in Corum watches. The tidal information is given on three subdials that share the face with a dates window at 3 o'clock. The local rise and fall of the sea level that can take place once a day (diurnal tides) or twice a day (semi-diurnal) depending on the location, is caused mainly by the gravitational pull of the moon and the sun.
The subdial at 6 o'clock shows the times of the next high and low tides as well as the hour on a 24-hour scale.
The red arrow with a + sign shows the time of high water, while the arrow marked – points to the hour of low tide. The hand shows the time on a 24-hour scale.
The subdial at 9 o'clock shows the state of the tide and the strength of the ebb or flood.
The hand points to a rising or falling tide on the semicircular scales of the subdial. When the hand reaches one of the red lines, it shows that the tidal current is at its strongest.
The phases of the moon and the coefficients for the tidal range are shown on the subdial at 12 o'clock.
When the moon is full or new it is aligned with the sun to exert the maximum gravitational force on the waters of the Earth and cause the highest and lowest tides (spring tides). The tidal coefficients are at their maximum (95-120) at spring tides. Tides with the lowest range (neap tides), with a co-efficient of 20-45, occur during the first and last quarters of the moon when the sun and the moon are pulling at right angles to each other.
Three pushpieces are used to set the three tidal indications according to the coastal location of the owner of the watch. The hours and minutes hands with Superluminova points are openworked so as not to obscure the tidal indications. The finely shaped centre-seconds hand is counterbalanced by Corum’s emblem, the key.
The 12-sided case characteristic of the Corum Admiral’s Cup collection has a diameter of 48mm and can be made in titanium or in red gold. Monochrome nautical pennants take the place of hour markers as a reminder of the model’s association with sailing.