Tide clocks feature an additional hand which records lunar time over a 24 hours 50 minute period and so indicates successive high and low tides

Explanation of the use of the tide clock
The tide indicator hand should be set to high tide when the next high tide in your location occurs. The exact time of the next high tide can be obtained from official tide tables. As a general rule the best time for setting the tide hand is at high tide during a new or full moon. If it cannot be set during a new or full moon then we recommend checking it at that time during the next cycle. The tide clock is not a perfect predictor of high and low tides during a moon phase however at the same location and at the same moon phase it is surprisingly accurate.