Hawaii waterman and environmentalist George Downing, a celebrated big-wave pioneer, surfboard designer, trusted mentor to generations of surfers and creator of the Quiksilver Invitational in Memory of Eddie Aikau at Waimea Bay, died peacefully in his sleep early Monday morning, his son Keone Downing said. He was 87 years old.

“To us that were close to him, George was the greatest surfer that ever lived,” said Gerry Lopez, a friend, confidant and champion surfer from a younger generation. “He was really the only one left that spanned pretty much the whole of modern surfing from riding solid wood boards to the foam shortboard.”

Born May 2, 1930, Downing began surfing at age 9 on a solid redwood plank at Waikiki. A paper boy, he bought his first surfboard from a homeowner along his route for $5, agreeing to pay installments of 10 cents a week. “He made it to $4.80,” said Lopez, “and he still has that board.”

At age 11, Downing became a beachboy at Waikiki, where he eventually ran beach concessions. He attended Washington Intermediate and, for a time, McKinley High School, but his education came through constant observation of the ocean and asking questions, Keone Downing said. “He learned economics and how to read people from the tourists coming at that time, because beachboys’ survival depended on tips.”

As a teenager, George Downing became one of the first to ride big waves at Makaha, along with older surfers such as Wally Froiseth and Woody Brown; he later won the Makaha International and competed in surf championships in Peru.

“I was really fond of him,” said famed Makaha waterman and lifelong Downing friend Buffalo Keaulana. As a youngster who didn’t have a surfboard, he would “hang around and caddy the boards” for Downing, Froiseth and Brown. He would body-surf, retrieving their boards when they wiped out and catching a wave or two before giving them back.

“It was beautiful with George here, and of course I’m gonna miss him.”

In 1985 Downing created the one-day, big-wave Quiksilver Invitational. Keone Downing said his father founded the now world-famous event “because he didn’t want to do just a surf contest; he wanted something special, and he wanted to do it a certain way.” He served as director of the event and was solely responsible for calling it on or off, for 30 years. Due to his exacting criteria, the contest has been held only nine times.

Downing, an innovative board shaper whose Dow­ning Hawaii surf shop in Kaimuki has been in business for decades, was also an early member of Save Our Surf, the local grass-roots environmental organization, and continued to lead its advocacy and educational work after founder John Kelly’s death.

“It was Duke Kahana­moku who shared with him that Waikiki is our most precious resource and told him, ‘Keoki, I leave you to take care of Mamala Bay, for she will take care of all of Hawaii,’” Keone Downing said, noting that his father devoted much of his later life to protecting Waikiki and Mamala Bay as well as other beaches and surf sites throughout the islands.

“George grew up with the Duke as one of his great mentors, and we and a number of my generation were so fortunate to grow up with George,” Lopez said.

Downing also will be missed as a father. “He taught me how to paddle a canoe. He taught me to surf,” Keone Downing said.

“He had so much humility and aloha,” Lopez said. “The world’s gonna be a lesser place without his wisdom, his great stories, the love he had not only for surfing, but for all of us, too. A very sweet and generous man.”

Funeral arrangements have not been announced. Downing is survived by sons Keone and Kainoa; daughter Kaiulu Downing; grandchildren Kaohi, Kirra, Kainoa, Keola and Nalei; and two great-grandsons; his wife, Gildea Lauwe Downing, predeceased him.