Tide is the vertical movement of the ocean surface caused primarily by the gravitational pull of the moon (and, to a lesser extent, the sun). Understanding how tide affects your local break is essential for choosing the right time to surf. Every break responds differently to tidal changes — some only work on a high tide, others only on a low tide, and many prefer specific stages of the tide. Ignoring the tide can mean paddling out to find flat, closing-out conditions or dangerous shorepound.
How Tides Work
The moon is pulling on the ocean as it orbits the Earth. The side of the Earth facing the moon experiences a slight bulge of water — this is high tide. The opposite side of the Earth (where the moon is pulling away) also experiences high tide, due to the centrifugal force of the Earth-moon system. Everywhere else, the ocean is at a lower level, creating low tide.
As the Earth rotates, different locations pass through these high and low zones, creating the regular cycle of tides. Most coastal areas experience two high tides and two low tides per day (a semi-diurnal tide). Some areas experience one high and one low per day (diurnal tide). The time between successive high tides is approximately 12 hours and 25 minutes.
Spring vs. Neap Tides
The size of the tide (the difference between high and low water) varies throughout the lunar month. During a new moon and full moon, the sun, Earth, and moon are aligned, and their combined gravitational pull produces the largest tidal range — the spring tides. Spring tides are not named after the season but from the old English word "springen" (to rise). During spring tides, the high tide is very high and the low tide is very low.
During the first and third quarter moons, the sun and moon are at right angles to each other, and their gravitational pulls partially cancel out. This produces smaller tidal ranges — the neap tides. Neap tides have a smaller difference between high and low water.
For surfers, spring tides (not to be confused with the season) tend to produce more dramatic, powerful wave conditions because the extra water volume makes waves break more strongly. Neap tides often produce smaller, weaker waves. This is a generalization — the specific effect depends on the local bathymetry.
How Tides Affect Different Breaks
Different breaks are affected by tide in different ways, and understanding your local break is key.
Beach breaks are often most affected by tide. At high tide, the water is deeper and waves break more gradually and gently, sometimes making beach breaks too soft and mushy. At low tide, the water is shallower and waves break more abruptly and powerfully, sometimes creating dangerous shorepound and making the impact zone more hazardous.
Point breaks and reef breaks often work best at mid-tide to high tide, when the wave has enough water to peel properly over the point or reef. At very low tide, these breaks can become too shallow and dangerous. Some point breaks only work at high tide and become a dangerous closeout at low tide.
The only way to know how your break responds to tide is to surf it regularly and pay attention. Note the tide height during your sessions and how the waves performed. Over time, you will develop a mental model of how your break behaves at different tidal stages, and you can use this to plan your sessions more effectively.
Tidal Streams
Beyond the vertical movement of the tide, the horizontal movement of water (tidal streams or currents) also affects surfing conditions. As the tide rises or falls, water moving in or out of estuaries, harbors, and channels creates currents that can help or hinder your paddling.
At some breaks, a rising tide (flood) creates favorable conditions with a slight current pushing you toward the lineup. A falling tide (ebb) might create an adverse current that makes paddling out more difficult. In extreme cases, tidal currents can create dangerous conditions in channels and around headlands.
When planning a surf trip to a new location, research the tidal patterns and how they interact with the local breaks. Tide charts are widely available online and in nautical publications. Many surf forecasting services include tide data alongside their swell and wind forecasts.