A pioneering drone lifeguard service rolled out across Spanish beaches saved the life of a 14-year-old boy this month as he struggled against a powerful tide off a beach in Valencia, its operators have said.

The drone dropped a life vest into the sea that was able to keep the teenager afloat just as he started to sink below the waves, until a physical lifeguard team arrived moments later.

"When we arrived what we saw was a kid that was in very bad shape, with almost no energy to keep floating, so I sent over the life vest," Miguel Angel Pedrero, drone pilot for General Drones, the firm that supplies the technology, told Reuters.

"Because of the heavy waves it was a complicated manoeuvre, but we finally managed to give him the vest and he could float until the lifeguards reached him by jet ski."

Valencia-based General Drones started supporting Spanish lifeguard staff in 2017 in the town of Sagunto just north of Valencia.

Now, it has more than 30 pilots and their drones working with the lifeguards at 22 beaches across Spain, providing rapid reaction support in the critical moments of a potential drowning before lifeguards can physically reach the scene.

"These extra seconds are vital in some cases and also allows the rescue teams to approach the person more calmly and cautiously," Pedrero added.

After being rescued, the 14-year-old, who has not been identified, was sent to a local hospital after ambulance personnel provided him with oxygen. He was sent home 24 hours later.

A total of 140 people have died from accidental drowning in Spain in the first six months of 2022, 55% more than in the same period of 2021, according to the Royal Spanish Lifesaving and Rescue Federation.