Time & tide clocks are most accurate for use on the Atlantic coasts of America and Europe.
Along the whole Atlantic Seaboard, the moon controls the tides predictably, ebbing and flowing on a regular schedule. However, on the Pacific Coast, the tides are irregular. The vastness of the Pacific Ocean makes it impossible for the moon to control the whole Pacific Ocean at once as it does in the Atlantic. It is not unusual for the Pacific Coast to have 3 high tides or 3 low tides a day. If a tide clock is used on the Pacific it will have to be adjusted frequently.
A full rotation of a tide clock, that is from one high tide to the next high tide, will take 12 hours and 28 minutes. Therefore, if you have a time and tide clock combination, you can expect to see the tide hand run approximately 1 hour behind the hour hand at the end of the first 24 hour rotation.
Weems & Plath recommends that the tide clock be reset with local tide charts approximately every 60 days. There are two setting knobs on tide and time clocks, one for setting the time and one for setting the tide. Be sure you are adjusting the correct knob. If resetting is done visually, its best to reset on a day that coincides with the full moon.