What is a Neap tide
During the moon's quarter phases the Sun and Moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons.
What is a Spring tide
When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a Spring high tide. Spring tides are especially strong tides (they do not have anything to do with the season Spring). They occur when the Earth, the Sun, and the Moon are in line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full Moon and the new Moon.
Dover Port is non-tidal, so most ships can come and go as they please.
Folkestone dries out at low tide.