Four teenagers cut off by the tide near the Boardmasters site in Newquay had to be rescued by the RNLI.
Volunteers rescued the group when they became trapped between Whipsiderry and Watergate Bay on Thursday afternoon.
They had tried to scramble to safety up rocks, injuring themselves in the process.
Both Newquay lifeboats launched, with a spokesperson saying: "The lifeboat crew took them to safety in challenging conditions through two-metre breaking waves and treated them for minor cuts and abrasions sustained on the rocks when they tried to reach safety."
It is not clear if the teenagers had been attending the Boardmasters festival in that area, but it prompted a warning from the RNLI to anyone attending this week's event.
An RNLI spokesperson said on social media: "The tide will come in high and fast in the afternoons this weekend. Look out for your mates and #RespectTheWater. In an emergency call 999 and ask for the Coastguard. #Boardmasters2018."
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