Marcos Ornellas was a water baby. He swam in pools and the ocean, competed with friends to see who could hold their breath underwater the longest. As a teenager, he loved few things more than the beach, surfboards and catching the perfect wave.

One overcast day in June 2023, the 15-year-old and his friends took their boards to Bolinas Beach, about an hour north of San Francisco. The waves were small, but they decided to make the most of the summer weather.

Out in the ocean, Marcos turned his board into the waves and paddled. A second later, he was up on his feet with the breeze in his face – his happy place. But as the shore quickly approached, he saw a group of about 20 young children taking surfing lessons right in his path. To avoid a collision, he dove into the murky water. The next thing he knew, his head slammed into a sandbar. His neck got warm. Then no feeling – no pain, nothing.

When he surfaced, he was floating face down in the water. He tried to right himself but found he couldn't move. "I was super confused," Marcos said. "I told myself: 'Just stay calm, stay relaxed, hold my breath, and my buddies will get me.'"

From beneath the surface, Marcos could hear his friends talking and laughing. "They thought I was messing around."

Almost a minute later, his friend Ryan realized something was wrong. "Ryan flipped me over, and I remember him asking, 'Marcos, what are you doing?'"

Gasping for air, Marcos responded, "I can't move."

Immediately, his buddies lifted him onto his surfboard and paddled him to the beach, where they called for help.