April is renowned for its full moon – the biggest and brightest of the year!
With this moon comes spring tides (‘spring’ being the name given to the tides with the biggest shift between high and low). Spring tides are caused by the gravitational pull of the moon and the sun aligning, and the combined force pulling the ocean in the same direction.
The week of the 26th of April 2021 saw some of the most extreme tides of the year. Tides this big will not be seen again until October 2021, so I took the opportunity to get some photographs.
Dawn light meets high tide at the UK’s only bar on a beach, The Wateringhole. On this day high tide and dawn corresponded almost exactly to the minute.
Built on an island of sand The Wateringhole is in danger of tidal flooding when spring tide coincides with a low pressure system and gale force winds, as happened in 2007.
High Tide & Low Tide by Jamie Turnbull
On the extreme tides this week the sea dropped a depth of nearly 7.5 metres between high and low.
These shots were taken on the same day, at exactly high and low tide. In the six hours between the two shots half a mile of beach has been exposed.
Penhale Cave by Jamie Turnbull
The extreme low tide makes accessible certain places that are usually underwater. These huge caves at Penhale Point can only be reached a couple of times a year.In the above shot the explorers have timed their visit perfectly, as the low tide gives only a short window between the caves being revealed and the sea starting to come back in again. Staying too long risks tidal cut-off, which is extremely dangerous (you can see a shot of people being cut off by the tide at Perranporth here).
Droskyn Caves by Jamie Turnbull
Looking out of one of the caves at Droskyn Point.
Exploring caves in Cornwall, and particularly Perranporth, can be dangerous. The danger comes not just from the tide, but from fact that many caves lead to mine workings – the mine workings here are the oldest in the country, dating back some 2,000 years. There have been both human and animal fatalities in the recent past and so if you’re planning on exploring caves then please be extremely careful.
Perranporth Lifeguards suggested I take a photo of the Lifeguard hut at Perran Sands on the extreme high tide, to help raise tidal awareness.
Many people are familiar with walking down the zigzag walkway at Perran Sands straight on to the beach, but seeing it with the sea up against it is a much rarer sight.
We’ve been working on a tidal awareness campaign with Perranporth Lifeguards… so if you’re visiting Perran Sands then look out for RNLI tidal awareness posters.
- For more images of Perranporth see our Perranporth Collection.
- For more information on tides see William Thomson’s excellent book ‘The Book Of Tides’.
- The Cornish Bird has a great write up on the history of mining at Droskyn, Perranporth.
- Information on beach safety can be found on the RNLI website.