New rules halving the number of pupils being taught by individual surf schools in Newquay have angered instructors.
Russell Winter from Newquay
The regulations, limiting numbers to 40, have been introduced in Restormel after lifeguards raised concerns about the rising number of surf schools.
The RNLI hope that next year every council in the county will adopt a similar scheme.
Instructors say although they welcome the increased emphasis on safety, the restrictions could cause more injuries.
Anthony Rowlett, of Newquay's Reef Surf School, one of seven schools in the resort, said: "We have quite successfully worked on teaching 60 or 80 pupils in a lesson, which might sound like a lot, but we work to the British Surfing Association (BSA) guidelines, which is a 10-to-one ratio.
"Now we are being told after seven years of hard work that we have to halve the ratios and that is going to ruin it for us."
He said the limits would force novice surfers to take to the beaches without any tuition.
"The other day we had someone come up to us with blood pouring from their face. They had been hit by a hardboard.
"It wasn't involved with our surf school, but they had gone out after hiring a board with no tuition and this is not an isolated incident."
Pete Craske of Surf's Up in Polzeath said it would simply encourage more surf schools to set up, causing greater problems in monitoring safety.
Reef Surf School warns more surfers could be hurt
He said: "We have up to 70 pupils at a time, but overcrowding is not an issue.
"There's no reason to cut numbers."
But Paul Benney, head lifeguard for the RNLI said: "A lot of surf schools were operating without the guidance of the British Surfing Association.
"They had instructors, but they weren't lifeguard trained and they possibly weren't trained in how to give tuition in surfing."
Those concerns prompted Restormel Borough Council to start the licensing system which means any surf school wishing to use the beaches must have a licence and be members of the BSA.
Restormel says it will review the situation at the end of the tourist season.
Young surfer Anna Gresham from Sheffield said she welcomed the new rules.
She said: "When we booked the holiday we just picked the first surf school we saw.
"You just assume that they are trained as lifeguards. It would be a bit silly if they weren't."