Memphis big man Marc Gasol has had an unconventional offseason.

The three-time NBA All-Star has spent the past week volunteering aboard the Open Arms Proactiva, a migrant-rescue vessel dispatched in the central Mediterranean Sea. On Tuesday, Gasol was photographed helping save a Cameroonian woman who had been drifting in the water for 48 hours, clinging to a piece of wood.

“There were pieces of wood and clothes floating in the water,” Gasol told The Guardian. “Then there was that woman, with her elbows resting on a wooden beam. Her eyes were lost in the void. She was weak and in shock. She had been clinging to that piece of wood with her last bit of strength and had remained that way for 48 hours. I thought of this woman, of her strength, and I felt anger.”

The woman, Josefa, had survived a shipwreck that occurred roughly 90 miles off the Libyan coast Sunday. In addition to Josefa, the bodies of two other migrants were recovered, including a toddler. Gasol said he would never forget the feeling of pulling the body of a small child from the water.

“I am a father. I have children,” Gasol said. “And I imagine the pain of a father who is forced to face a journey like this where one risks everything, one risks one’s own life, to reach a country where one can live in peace and with dignity.”

Gasol has worked closely with non-governmental organization Proactiva Open Arms, a nonprofit group that rescues refugees attempting to escape wars, persecution or poverty. At first, the Barcelona native was hesitant to publicize his humanitarian work, but after experiencing the horrors of the rescue missions, Gasol decided to use his platform.

“Frustration, anger, and helplessness,” Gasol wrote in a tweet Tuesday. “It’s unbelievable how so many vulnerable people are abandoned to their deaths at sea. Deep admiration for these I call my teammates at this time @openarms_fund.”

The 33-year-old will soon return to the U.S. for his 11th season with the Grizzlies, bringing his unforgettable experiences with him.

“I cannot understand how anyone can turn away from these people who are dying at sea,” he said. “How can we pretend it isn’t happening? Before being an athlete, I’m a person, a human being, like the ones Open Arms are saving every day. We must work so that these tragedies never happen again. We are all responsible.”