Check offshore wave observations and local weather conditions around Cornwall before heading to the beach. Compare readings from the north and south coasts, alongside the wider offshore marine conditions.
Explore the buoy locations and the St Ives Bay surf area. Select a marker to see which station it represents.
Buoys measure conditions at their own offshore locations, not directly at individual beaches. Porthleven is a regional reference for Praa Sands, not a direct measurement from the beach. Wave height and direction can vary significantly between offshore stations and the shoreline. Check local conditions and official safety advice before entering the water.
Learn how to read a surf forecast and understand the wave height, swell period, swell direction, wind and tide affecting surf conditions around Cornwall and St Ives Bay.
A surf forecast might say 4ft, but that number alone
doesn't tell you how the waves will actually feel.
A short-period wind swell can produce very different
waves from a longer-period Atlantic swell of the same
height.
To understand surf conditions in Cornwall, read the
numbers together: wave height, swell period, direction,
local wind and tide.
Wave height tells you the size of the waves being
measured at the buoy or forecast location. It gives
you a useful indication of the overall offshore sea
state.
It does not necessarily mean that the waves breaking
on a beach in St Ives Bay will be exactly the same
height.
Wave period is the time in seconds between successive
wave crests. It is one of the most useful numbers in
a surf forecast.
Longer-period Atlantic swell generally carries more
energy and can produce more powerful waves when it
reaches suitable beaches.
Swell direction tells you where the incoming swell is
coming from. This matters because Cornwall's coastline
faces different directions and individual beaches are
exposed to different parts of the Atlantic.
A large swell offshore can have much less effect on a
sheltered beach.
Wind can dramatically change the quality of surf.
Offshore wind can help groom the wave face, while
onshore wind can create chop and make the waves less
organised.
Always look at the local wind as well as the offshore
swell.
Tide changes the depth of water over the seabed and
can dramatically alter how a wave breaks.
The same swell can look completely different at low,
mid and high tide depending on the beach and its
seabed shape.
The final step is looking at the actual beach. Forecasts and buoy observations describe what is happening offshore and around the coast. The beach is where all those factors come together.
Here's a simple example of how to interpret a surf forecast. Instead of looking at the wave height on its own, combine it with the swell period, direction and local wind to build a much clearer picture of the conditions.
Around 5ft of wave height with a 12-second period describes an organised swell rather than simply a short wind-generated sea. The WNW direction then helps identify which parts of the Cornish coastline are most exposed to that swell.
Now add the local wind and tide. If the wind is favourable and the beach is exposed to the incoming swell direction, the conditions can look very different from a nearby sheltered beach.
Wave height tells you how big the
offshore sea state is.
Period tells you about the spacing and
energy of the swell.
Direction tells you which coastline is
exposed.
Wind affects the surface and wave
quality.
Tide changes how the waves interact
with the seabed.
Put all five together — then look at the beach.
That's when a surf forecast really starts to make sense.
