The death of a 15-year-old boy near Adelaide's Glenelg beach, the tenth such drowning across the country this summer, has forced lifesavers to warn beachgoers about water safety.
Surf Life Saving Australia (SLSA) is alarmed by the total, up from eight coastal drownings in the same period last year, together with the fact that half of those killed have been aged 15 or under.
The teen was pulled from waters near Glenelg jetty on Monday afternoon but could not be revived.
"It's another young person whose life has tragically been taken," SLSA national coastal risk and safety manager Shane Daw told AAP.
Of all presumed sea drownings so far in December, five have been in NSW, three in South Australia, one in Tasmania and another in Queensland.
It sends a strong message that incidents can happen all too quickly, Mr Daw said, and often before people know anything is wrong.
He encouraged people to swim at patrolled beaches, between the red and yellow flags, and heed any safety signs.
Learning to recognise a rip current is also important, as is assessing safety conditions before entering any water.
"If you're unsure, stay out," Mr Daw said.
