A single handed Tide movement. The hand rotates at 12 hours and 25 minutes to the normal 12 hour rotation of other clocks. This is half the lunar cycle of 24 hours 50 minutes which governs high and low tides.
Takes a single Alkaline AA battery order separately under tools.
Note that the 24 hour 50 minutes is an average figure based on a 29 1/2 day cycle. Actual high and low tides may vary due to local wind conditions causing tides to be slightly earlier or later than indicated.
For dials up to 6mm thick.