潮汐钟是一种依据月球环绕地球的视运动特别设计的钟。沿着海岸线的许多潮汐，都是太阳和月球联合的潮汐，但是月球仍占了主要的成分（67%） 。

潮汐钟的运转依据月球潮汐高潮的时间间隔，12小时24分钟的平均值。在钟的底部标示为低潮，而在顶端标示为高潮，钟表盘面的左侧标示距离大潮的小时数，由5小时倒数至1小时。在钟面上有一根指针，在钟的左面指示出还有多久涨到最大潮（月球潮）。钟表盘面右侧标示的是距离低潮的时刻，也是由5小时到1小时的倒数计时，指出的数值也是月球潮的低潮时间。

有些潮汐钟的指针显示高潮或低潮是以倒数计时的，像是显示已过高潮或低超一小时等。而当指针抵达潮汐的半途，对时间的计算会成为距离高潮或低潮还有一小时等。

A tide clock is a specially designed clock that keeps track of the Moon's apparent motion around the Earth. Along many coastlines the Moon contributes the major part (67 percent) of the combined lunar and solar tides. The exact interval between tides is influenced by the position of the Moon and Sun relative to the Earth as well as the specific location on earth where the tide is being measured. Owing to the Moon's orbital progress, it takes a particular point on the Earth (on average) 24 hours, 50.5 minutes to rotate under the Moon, so the time between high lunar tides fluctuates between 12 and 13 hours. A tide clock is divided into two six-hour-long tidal periods that shows the average length of time between high and low tide in a semi-diurnal tide region such as most areas of the Atlantic Ocean. Therefore, compared with the actual time between the high lunar tides, tide clocks gain approximately 15 minutes per month and must be reset periodically.