Neap Tide

When the difference between high and low water is at its smallest, typically occurring twice a month during the first and third quarters of the moon.

A neap tide is a natural tidal phenomenon that occurs when the gravitational forces of the moon and the sun are at right angles relative to the Earth. This alignment happens during the moon’s first and third quarters when the moon appears as a half-circle in the sky. During a neap tide, the tidal range – the vertical difference between high tide and low tide – is significantly reduced compared to a spring tide. This is because the moon’s and the sun’s gravitational pull partially cancel each other out, resulting in weaker tidal forces. 

In practical terms, neap tides produce less dramatic water level changes, which can affect navigation, anchoring, and mooring for vessels. For example, sailors and boaters may find that specific shallow channels or harbours become less accessible during neap tides due to the reduced water depth at high tide. Conversely, the smaller tidal range can also mean less risk of strong tidal currents, which may be advantageous for activities like docking or manoeuvring in confined spaces. Understanding neap tides is essential for mariners planning their routes and operations, as it directly impacts water levels and tidal currents, both critical for safe and efficient navigation.