Explanation:

Tide is the vertical rise and fall of the sea level surface caused primarily by the change in gravitational attraction of the moon, and to a lesser extent the sun. At the new and full moon, the sun and moon are in syzygy (three celestial bodies in a straight line). Their tidal forces act to reinforce each other, and the ocean both rises higher and falls lower than the average. Conversely, at the first and third quarter, the Sun and Moon are at right angles, their tidal forces counteract each other, and the tidal range is smaller than average. Spring tides have higher high tides and lower low tides whereas neap tides have lower high tides and higher low tides.