High tide occurs when the area of the ocean or sea is aligned with the moon due to the moon's gravitational pull causing a bulge of water, which manifests as high tide. This bulge happens both on the side of the Earth closest to the moon and the opposite side, resulting in two high tides in most coastal areas every lunar day. A lunar day is about 24 hours and 50 minutes, which means that high tides typically occur about every 12 hours and 25 minutes. So, for most coastal locations, there are two high tides and two low tides approximately every 24 hours and 50 minutes. The height of high tide changes throughout the lunar month. The highest high tides, called spring tides, occur roughly 36 to 48 hours after the full moon or new moon when the sun, moon, and Earth are aligned, reinforcing the tidal forces. Lower high tides, called neap tides, occur about a week after spring tides when the sun and moon are at right angles relative to the Earth. In summary:

• High tides occur when the moon's gravitational pull causes ocean water to bulge at the location.
• Two high tides occur each lunar day (about 24 hours and 50 minutes).
• The timing is roughly 12 hours and 25 minutes apart.
• The highest tides (spring tides) happen near the full and new moons due to alignment of the sun, moon, and Earth.
• Lower tides (neap tides) occur around the moon's first and third quarters.

The exact timing of high tide at a specific location varies based on the moon's position, local geography, and ocean bathymetry but generally follows this pattern.