Ma told KGO that she asked whether Chan needed her to pull her to the beach.
“She said, ‘No, no, I can swim by myself. I just can’t kick because the sea lion bit me on my knee,’” Ma said.
Former San Francisco Fire Department paramedic Jeany Duncan and Dolphin Swim and Boat Club member Lee Hammack were also in the water when the attack took place, according to SFGate and KGO.
"She was bleeding pretty badly," Hammack told SFGate. "But I know her -- she's tough, she's not scared."
Chan was able to walk on her own after the attack and did not appear to be seriously injured, SFGate reported.
"She was just more shook up than anything as anybody would be," Duncan told KGO.
The attack was the fourth reported in the last month involving sea lions, according to SFGate.
The attacks last month prompted National Park Service officials to close Aquatic Park Cove to swimmers for several days. It was reopened Dec. 20.
“Although the immediate hazard seems to have passed, the park wishes to remind all visitors that marine mammals are wild animals, in their natural habitat, and that their behavior can be unpredictable,” NPS officials said last month in a news release. “The frequency of recent sea mammal bites reported was abnormally high, but interactions between marine mammals and swimmers do occur. If visitors choose to swim, the park recommends that they take precautions, including keeping at least 50 feet away from sea lions or harbor seals.”