(CBS News) - Dylan McWilliams was paddling into the line-up at Shipwreck's Beach off Poipu Thursday morning when he felt something bite down on his leg.
"I was looking around and saw a bunch of blood," the 20-year-old visitor from Colorado told CBS Honolulu affiliate KGMB-TV.
That's when he saw the culprit: A shark swimming just underneath him.
McWilliams started kicking wildly, then swam toward shore.
He was about 50 yards from the beach and was panicked that the shark might follow.
"The scariest part was swimming back," he said. "There was blood behind me. I didn't know where it was."
McWilliams suffered deep cuts to his leg, but the injury wasn't life-threatening.
When he got to shore, bystanders helped him and he was taken to an urgent care center for treatment.
Adding to his ordeal, when he arrived at the hospital, there was a one-hour wait to see a doctor. He waited and was eventually stitched up.
Ocean Safety officials closed Keoneloa Bay after the incident, but it's since been reopened.
As for McWilliams, he's not going to let the run-in keep him out of the water.
"I'm just mad that I can't get back in the water for a couple days," said the visitor, who's on Kauai for two weeks on a backpacking trip.
And this isn't his first encounter with a sizable creature with big teeth.
About seven months ago, McWilliams says he was camping with some friends in Colorado when a 300-pound black bear went straight for him.
"The bear grabbed the back of my head and started pulling me and I was fighting back as best as I could," he said. "It dropped me and stomped on me a little bit, and I was able to get back to the group and they scared it away."
He says he's lucky to have survived both encounters, and his love for being outdoors can't be shaken.