Claire Sugden MLA said the Causeway community has been left in shock following the death of a teenager in the sea near Dunluce Castle on Tuesday evening.
It's believed the group of boys, from the Belfast area, had been jumping off rocks into the sea below Dunluce Castle in a practice known as 'tombstoning'.
The young man was pronounced dead at the scene, with a second person treated for minor injuries. Two further boys were unharmed.
Ms Sugden commended the efforts of the young man's friends who tried to save his life.
"It is heartbreaking to lose such a young life" she said.
"I offer sincere condolences to his family and friends. I commend those young people who made every effort to rescue their friend and also the emergency services who attended the incident and brought others to safety.
"As we emerge from lockdown and the weather improves of course we want to enjoy time outside and in the sea.
"But our waters can be dangerous particularly if you were unfamiliar or inexperienced."
Coastguard teams from Portrush, Ballycastle and Rescue 199 from Prestwick rushed to the scene on Tuesday night along with the ambulance service and the PSNI.
Sinn Fein MLA Caoimhe Archibald sent her condolences to the family of the teenager who lost his life.
"This death is a tragedy and my thoughts are with his family and friends," she said.
Maurice Bradley MLA added his condolences.
"It's a tragedy," he said.
"The north coast is a wonderful place but a very dangerous place."
Judith McNeice from the Maritime and Coastguard Agency issued a warning about the dangers of the sea off the north Atlantic coastline.
"Although it was an absolutely beautiful day the north coast is notorious for having a large swell even in the most benign weather.
"There is a risk even on the most lovely day for people swimming or jumping from rocks.".
The PSNI said they are not treating the death as suspicious.