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One of the more interesting and entertaining aspects of surfing, apart from the obvious is trying to predict surf - something you'll often hear experienced surfers discussing 'ad infinitum'.

The reason it's such a varied topic of conversation is that there are so many variables to consider. These include Atlantic lows, local weather, winds, tides, swell direction, size, wave period not to mention the physical aspects of each individual beach - reef, sand banks etc.

Wave buoys are just another tool to help you understand the surf conditions and accurately predict what is going to happen at your spot.

The following is all based on my own surfing experience over a number of years here in Wales. I'm not a scientist or expert in any way, shape or form.

Wave buoy terminology

At first glance, there is a lot of information to try and make sense of, so here are some of the more relevant things you need to consider.

AVP = Average wave period is a measurement in seconds of the distance between waves, passing the wave buoy.

The longer the period between waves, the better the waves will be. Three seconds is poor, however ten seconds is good and will provide a proper groundswell with well defined lines of surf at the beach.

WVHT = Wave height is a measurement of the size of the passing swell at the buoy's location.

This is taken from the rise and fall of the buoy above and below mean sea level and measured in feet or meters. The bigger the measurement, the better the surf.

WDIR = Wind direction which is the direction that the wind is blowing from at that particular wave buoy location. Winds can however change locally though.

WSPD = Wind speed indicates how fast the wind is blowing. This is measured in knots, meters per second, miles per hour and kilometres per hour.

In this case, the lower the measurement the better, no matter what the wind direction is.

Which wave buoys to use in Wales?

Surfers in South West Wales normally use the data which provides swell information for Pembrokeshire and Gower beaches.

Surfers in South Wales however use the which is more local to their beaches.

The can all be found here but I'll concentrate on the Pembroke wave buoy to keep it simple.

Estimates of wave size at the beach will be based on Llangennith beach, Gower. Rest Bay in Porthcawl and Freshwater West in Pembrokeshire, are the other main, swell indicators.

I've already mentioned that there are many variables to consider, so I've condensed and generalised the information below to serve as a guide for less experienced surfers.

The more experience you gain, the more accurately you'll be able to read the information for yourself.

The table below explains approximately what the measurements mean for a fairly calm, windless day. It does not factor in any local wind variables:

In summary, the bigger the wave period, (the period of time between each wave), the larger the wave is likely to be at the beach.

On the Pembroke buoy it's unusual for the period to be greater than 10 seconds but it does happen and can occasionally go as high as 17 seconds.

Article written by Kev 'Doc' Child