The term 'Third-Quarter Tide' refers to a type of tide known as a NEAP tide. NEAP tides occur when the sun and moon are at right angles to each other, resulting in a weaker gravitational pull on the Earth's oceans. This causes the ocean's water level to be lower than normal, creating a third-quarter tide. These tides are usually seen twice a month, around the time of the first and third quarter moons.