Good Samaritans helped rescue a 71-year-old snorkeler at Kahe Point on Sunday.
"She's yelling help and she had her friend, and her friends face down in the water, and she's yelling help me help me," said Karrie Wroten.
Beach goers said they saw five women at Electric Beach Park snorkeling together. One of them went missing.
"They were out as a group, and she'd pop her head up, and would count for five of them periodically, and then all of a sudden there were only four," said Carolynn Rittermann.
Witnesses said a friend swam up to the woman floating face down, but didn't get a response, so she started screaming for help.
"The two guys ran out and got her, swam up, brought her up on the shore, and immediately started working on her, they yelled call 911," said Wroten.
Bystanders said emergency help came within 10 minutes. The woman was taken to the hospital in critical condition.
Witnesses said the group of women are from Ohio and are visiting Hawaii for a conference. Bystanders were told it was there first time snorkeling.