Images showing the turtle before its rescue are courtesy of Jason Kunewa/Dana Wharf Sportfishing

A massive leatherback turtle that had become entangled in kelp off Orange County is free, thanks to the heroic efforts of  Dana Wharf Sportfishing crewman Jason Kunewa.

Kunewa and Capt. Bo Daniels were 15 miles offshore aboard the San Mateo on Sunday, searching for tuna and whales, when they spotted what they thought was a large kelp paddy.

“Then I saw a head come out,” Kunewa said. “It was the biggest turtle I’d ever seen. It was longer than me and about three times as wide.”

The 6-foot-long turtle, weighing perhaps 1,000 pounds, was dragging a heavy clump of kelp and tightly wrapped on its left front flipper and around its neck.

Kunewa said the animal had trouble swimming, so he grabbed a fillet knife and jumped overboard. He reached for the trailing end of kelp first, and cut about half of the mass away, then returned to cut the constricting strands from the flipper area.

He managed to cut some of the kelp that was wrapped around the flipper, without grabbing the flipper, and the rest loosened and floated away.Only a few loose strands remained in the neck sea when the turtle, sensing its newfound freedom, bolted “like a bat out of hell.”

Leatherbacks are the largest turtles on the planet, reaching lengths of nearly 10 feet and weights of about 2,000 pounds.

They’re found in tropical and temperate waters around the world, mostly in pelagic zones where they prey on sea jellies, and are classified as endangered in U.S. waters.

Sightings off Southern California are rare.