Each day, there will be four changes of tide. Every six hours, it will change from low to high or high to low. Therefore, every twelve hours, each type of tide will repeat itself. They are distanced in this increment because of the time it takes the moon to orbit the earth.
The difference in force is caused by the position of the moon in accordance with the sun. If the moon is alligned with the sun and earth, then there will be high tides where the moon pulls on the earth as well as the part of the world opposite that. In result, the other two corners of the world that are opposites will experience low tides.
When the moon pulls on a certain part of the world, it creates a tidal bulge which is an excess amount of water which then creates a high tide.
A spring tide occurs when the sun, moon, and earth are all lined up with each other and will result in extremely high tides. This only happens during a full or new moon. In contrast, a neap tide is when the moon is positioned on the right or left of the earth and there is less of a direct pull from the moon. This results in extremely low tides.
Right now (9:34 pm), the tide in Bogue Inlet is rising. The moon at this beach is not full or new, which means that it is currently experiencing a neap tide.
