When the two conspire, they cause a spring tide; when the solar and lunar tides are opposed, we have the neap tide.
The spring tide is lunar plus solar; the neap tide is lunar minus solar.
When the two agree, we get a spring tide of four feet; when they oppose each other, we get a neap tide of only two feet.
Vessels drawing 20 ft. can enter the new docks at neap tide.
A tide in which the difference between high and low tide is the least. Neap tides occur twice a month when the Sun and Moon are at right angles to the Earth. When this is the case, their total gravitational pull on the Earth's water is weakened because it comes from two different directions. Compare spring tide. See more at tide.