The action of the tide is very complex and involving many factors which must be considered to describe the tide at any given place, and the calculations necessary for compiling the official Tide Tables are usually done by computers. The tide clock does not claim to give you exact time of each if the tides at a given place, but, it will give you the average value of the time, which is all the average person needs to tell him when he can go boating, fishing, surfing, etc.
The primary controller of the tide is the moon and the average duration between two transits of the moon around the earth is 24 hour 50 minutes and 30 seconds, and is referred to as the "lunar" or "tidal" day. This means that the tidal day - to which the tide indicating hand of your Tide Clock is geared - is 50 minutes longer than the solar day of 24 hours, to which the hands of your clock are geared. In other words your Tide Clock movement has four hands - the tide indicating one, running 50 minutes late every 24 hours, and thus indicating the average times of the tides at a given point, the regular hour, minute, and second hands, giving you the regular time of the day. To put your Tide Clock in operation please proceed as follows:
Open the front of the clock. Please insert a fresh Alkaline size AA (such as Duracell) 1.5 V battery. Insert the battery the correct orientation, observing the + and - markings on the battery compartment.
A) At the back of the movement you will find the hand set knob, which is for setting the regular clock hands. Below the movement you will find the set-wheel for setting the tide indicator hand.
B) Always set the clock hands before setting the tide hand. The tide indicator should be set to high tide by means of the set-wheel when the next high tide in your location occurs. The exact time of the next high tide can be obtained fron the official tide tables in your location, from the Harbour Master, or offices of most shipping companies. As a general rule, the best time for setting the tilde hand is at high tide during a new or full moon. If there should just happen to be a full or new moon when you first set your tide hand, then fine. If not, we suggest you check the reading if the tide hand at the exact time of high tide at the next full or new moon. If at that time your tide indicator hand is not pointing exactly to HIGH TIDE, then adjust it with the set-wheel. From now on, a further adjustment to the tide hand should not be necessary.
Your clock is set at the factory for a deviation of accuracy of approximately 1 minute per year at room temperature of 20 degrees C plus or minus 3 degrees. Please note that large temperature changes will affect the accuracy.
The West coast of Europe and Africa, also the East coasts of North and South America follow the "semi-diurnal" pattern of the two high and two low tides a day ("tidal day of 24 hours 50 minutes) more or less equally spaced. Certain other coasts around the world such as the West coasts of North and South America are not semi-diurnal, and the tide indicating part of your Tide Clock will be of no use to you in these areas. However, the time telling part of course is correct worldwide.
Please remember that any alteration of the hands (such as setting for Daylight Saving Time) will automatically cause an alteration of the tide hand, as both operate in conjunction with one another. Therefore, after any major alteration of the setting of the time hands, the tide hand should be reset as described in paragraph 3.