The man has been identified as Nicholas Johnson, 19, a sophomore majoring in psychology.
Before attending UCSB, Johnson competed for Santa Barbara High School’s water polo and swimming teams. He also played on the water polo team for the Santa Barbara Aquatics Club.
He is the oldest of four siblings, and his parents, Berkeley and Karen Johnson, posted a short statement on Facebook Monday afternoon.
"It is with infinite sadness that I let everyone know that our oldest son, Nick Johnson age 19, passed away this morning while doing a hard swim set at Santa Barbara High School," Berkeley Johnson wrote.
"He was surrounded by fellow swimmers and lifeguards and they did their best on the pool deck. The doctors in the emergency room also made every effort but could not revive him. Karen and I simply do not know what to do. We want to thank all of you for your heartfelt condolences and we'll go to ground at home and try to regain our equilibrium. Nick was a sweet boy and I cannot tell you how much we all will miss him."
Emergency crews were called out to the campus at about 9:45 a.m. on a report of a possible drowning, and immediately began treatment on the victim, said Sgt. Riley Harwood.
Johnson used the pool for his own practice session while the high school swim team was doing laps, Harwood said.
Several of the swim team members noticed him unresponsive at the bottom of the pool's deep end, and three with life-guard training pulled him up and immediately began CPR, Harwood said.
"It was described to me as a 'heroic effort,'" he said.
The victim was treated at the scene, then transported to Santa Barbara Cottage Hospital, where he later was declared dead, Harwood said.
As with any death investigation, police are investigating and will forward the case to the Santa Barbara County Coroner's Office if there is nothing suspicious about the circumstances, Harwood said.
The Santa Barbara Unified School District is on spring break this week, but the swimmers were on campus, with a coach chaperone, for training, district spokeswoman Barbara Keyani said.
"Folks here were all pretty distraught," Harwood said.
Hospice Care counseling support has been offered to the family and Save A Valuable Employee (an employee assistance program) is available to district employees, Keyani said. School psychologists and counselors will be available to students and staff members when school returns from spring break next Monday.
"We extend our deepest sympathy to the family," Keyani said.
The loss has hit the UCSB campus hard, Intercollegiate Athletics Director Mark Massari said.
"Our thoughts are with his entire family, parents Karen and Augie, and everyone who knew and loved Nick," he said in a statement. "Right now we have set up counseling support with the campus for all our student-athletes and staff as we grieve.”
Wolf Wigo, the UCSB water polo coach, called Johnson "the best kid, hardest-working kid, a first-class person and a wonderful students and brother to his teammates."
"I was lucky enough to be his first coach, and along with everyone in the UCSB family and water polo community, I will miss him greatly," he said.