"Fierce" rip currents are making some beaches in north Cornwall dangerous, lifeguards have warned.
They have identified 16 rip currents on Perranporth beach, some of which are up to 100m wide.
A rip current is a strong channel of water that pulls swimmers and surfers away from the shore.
Senior lifeguard Sam Chamberlain said the rips were "especially fierce at the moment" on some beaches and urged people to follow safety advice.
He said: "I've not seen the beach like this for about six or seven years. We always have one or two rips on the beach but these big ones are not usually there.
"They started smaller this year and have just grown, and the recent storms have carved them out really deep."
He added: "A lot of the north coast beaches have had a problem with rips this year.
"It's a bit like roulette. Some seasons it will be really safe with nice flat beaches and other seasons will see big gullies and strong rips. It's all affected by wind, surf and tides sculpting the beach."
Lifeguards put the current condition of the beaches down to recent stormy weather, with strong north westerly winds "making the rips especially fierce at the moment".
Other beaches affected by rip currents currently include Porthtowan, Chapel Porth and Holywell.
People are advised to only go in the sea at lifeguarded beaches and to take particular care this weekend, when there are some of the biggest tides of the year.
The advice from the RNLI if you are caught in a rip current is:
- Don't try to swim against it, you will quickly get exhausted
- If you can stand, wade don't swim
- Swim parallel to the shore until free of the rip and then head for shore
- Always raise your hand and shout for help