THE Westpac Helicopter Rescue Service Gold Coast was in the right place at the right time 11am (Qld) today.

A 17-year-old boy was rescued from Snapper Rocks by rescue swimmer Shane Watson, aircrew Brett Dorrington and chief pilot Peter Bird.

Mr Bird said he was seen struggling by the chopper crew on a sand bank near Froggy's Beach.

"He seemed to be okay at the time," he said.

"So we turned to have another look when he was hit by a wave and pushed into rocks.

"He was trying to swim back out, and we decided he was in a fair amount of difficulty.

"He was fairly close to the rocks when we put our guy into the water.

"Our rescue swimmer had difficulty getting to him and once the rescue harness was on him we flew back out to sea.

"Then we took him around the corner into Duranbah, landed at the Volunteer Marine Rescue helipad and recovered our rescue swimmer."

He said the boy was having difficulties for about 15 minutes and had tried to climb up the rocks but was "getting smashed".

"We see a lot of swimmers using the backwash there, but it's a pretty dangerous spot to be in."

The rescue was an unexpected part of a "typical roving patrol", Mr Bird said.

"Surf Life Saving Queensland is a very proactive service.

"We operate from the border right through to Noosa's north shore.

"We're checking for sharks or any marine life we don't want near our swimmers, and making sure everyone's where they're supposed to be.

"When they're not we winch them up and put them back on the beach."

He said he had seen about 10 riderless jet skis floating in the ocean over the Christmas period, and the service always followed up riders' whereabouts.

"Sometimes we'll see boards floating without riders, so we'll call lifesavers and make sure as to where they are."