Hawaiian surfing legend Vincent 'Sunny' Garcia is in a critical condition after being found unconscious at his home in Oregon this week.

World Surf League confirmed Garcia, 49, was rushed to Portland hospital where he remains under intensive care.

"Sunny has always been a great champion of surfing, both in and out of the water. Our prayers are with him and his loved ones at this deeply challenging time," a statement from the organisation read.

One of the most recognisable names in competitive surfing, Garcia holds a spot on the Surfing Walk of Fame. He was crowned world champion in 2000 and claimed the triple crown - awarded to the best surfer across three major events in Hawaii - a record six times.

Garcia had been open about battles with depression over the years, writing about his troubles in a post on Instagram in 2014.

"Depression is no joke," he wrote. "Waking up feeling like you're ready to take on the world then a couple hours later feeling down on life and wondering what's wrong with you. Well I know I'm not alone and I'm not sure what's wrong with me because I have no reason to feel the way I do and it's been happening for about two years and I would love to hear from any of you who suffer these feelings so I can figure out what I should do."

Surfers around the world have voiced their concern and support for Garcia, including 11-time world champion Kelly Slater.

Slater and Garcia competed together on the championship tour in the 1990s and early 2000s, both winning world titles during the period.

"I love you, brother. I just can't even fathom you not here," Slater posted on Instagram. "We've got so much more living to do before we are done. There's been hard times but there have been so many good ones, too. Just praying you wake up and we get more of you."