If you’re serious about coastal foraging or fishing along the British coast, understanding the tides is an essential skill. A misjudged tide can mean arriving too early or too late for the best pickings, wasting hours of effort, or worse, finding yourself stranded by rising waters.
For those who know how to read a tide table properly, the rewards are well worth it—exposed mussel beds, freshly uncovered razor clam burrows, and fish moving predictably with the current.
Understanding High and Low Tide
Tides are the rise and fall of sea levels caused by the gravitational pull of the moon and sun. Along the British coast, there are typically two high tides and two low tides each day. High tide is when the sea reaches its peak level, covering rocks and beaches, while low tide is when the water recedes, revealing stretches of seabed, tidal pools, and marine life. The difference in height between high and low tide varies depending on location and whether it’s a spring or neap tide.
For coastal foragers, the best time to head out is as the tide is going out. This allows you to follow the water as it recedes, ensuring that what you gather has only just been uncovered rather than sitting exposed for hours. Shellfish, seaweed, and other coastal edibles are in the best condition at this stage—still fresh, hydrated, and less affected by sun, wind, or predators.
How to Read a Tide Table
A tide table provides essential data for planning a trip along the shore. It lists:
- High and low tide times – showing when the tide will be at its highest and lowest.
- Tidal heights – the expected water level at each tide, measured in metres above chart datum.
- Spring and neap tides – spring tides have the greatest difference between high and low water, exposing more of the shore, while neap tides are more moderate.
By checking a tide table, you can time your coastal foraging or fishing trip to coincide with the best conditions. If you’re foraging, aim to start about two hours before low tide and work outward as the sea recedes. This way, you avoid unnecessary risk and get to areas before they’ve been dried out or disturbed. For fishing, the timing will depend on the species, but many predatory fish move into shallower waters on a rising tide, making flood tides a prime time to cast a line.
How Tides Influence Coastal Ecosystems
Tides dictate the movement and behaviour of marine life. Shellfish such as cockles, mussels, and oysters rely on tidal currents to bring in food-rich seawater and they live in the intertidal zone, or at the very lowest point of it, making them most accessible at low tide. Razor clams, which burrow rapidly, can be caught as they are briefly exposed when the sea has just uncovered their burrows. Seaweed, which thrives in intertidal zones, is best harvested just after being uncovered to ensure freshness and minimal damage.
Fish adjust their movements based on the tide. Bass and other predators follow the rising water, hunting in newly submerged areas, while flatfish settle into estuarine mudflats when the tide is out. Crabs and lobsters shift between hiding in crevices at low tide and venturing out to feed when the water returns. Understanding these patterns allows for more efficient and sustainable harvesting.
The Impact of Wind and Rain on Tides
Tides don’t act in isolation. Wind and rain can subtly but significantly alter them. Strong onshore winds push water higher up the shore, making high tides even higher and low tides less pronounced. Offshore winds can do the opposite, revealing more of the seabed than expected.
Rainfall, particularly in estuaries and tidal rivers, affects salinity levels and can push mobile species further out to sea. Heavy rainfall or snow-melt can also artificially increase the height of the water at high tide in estuaries as the river water collides with the sea and the two combine to create a larger volume of water than usual. Stormy, squally weather can also stir up sediment, reducing visibility for fishing and making some foraging areas less productive.
Navigating the Shore Safely
Misjudging the tide can be dangerous and need to be understood, particularly by group leaders. A rapidly rising tide can cut off escape routes, especially in areas with gullies, sandbanks, or steep cliffs. Even at low tide, sudden waves or shifting currents can catch people unaware. Always plan your exit route before setting out, and check local conditions to avoid getting stranded.
Developing an Eye for the Tides
Reading a tide table is just the start—experience will refine your understanding. Observing how the water moves, noticing how different shorelines are exposed or submerged, and recognising how marine life responds to changing conditions will make foraging and fishing more productive. By working with the tides rather than against them, you’ll make the most of each trip while staying safe and respecting the environment.
Every year Wild Food People run a calendar of foraging and wild food courses in North Wales.
From forests and meadows to seashore and coastal – all of our courses are focused on food, ecology and giving participants the confidence to go and find these foods for themselves.
We work with nature.
We deliver expert foraging and wild food training as part of our wider work managing habitats in North Wales.
Every single one of our courses and events feeds back into improving those habitats, helping to provide healthy ecosystems for our local wildlife and communities.