Brandy Mosley, 33, went missing after swimming into the water to help her 4-year-old child who was having trouble swimming, officials said.
Her toddler was wearing water wings and playing on the sand at the edge of the gulf. A wave carried him into the water.
Mosley and another family member rushed to save him. The child and the relative made it to the shore, but Mosley was nowhere to be found.
"What's really sad is seeing the rescue plane going back and forth," said witness Laura Blackburn. "Looking and looking. We all looked for an hour or two, a couple of hours just looking for her."
Mosley was last seen wearing a gray shirt and maroon shorts.
Blackburn said the water was rougher Monday than it had been. Like Mosley, who was visiting from Palestine, Blackburn is a visitor here.
Residents said the currents are deceptively dangerous.
"They just don't understand how dangerous it is to these people out here," said Ann Lawrence, who lives in Bolivar. "A lot of them are out-of-town vacationers. They just don't understand how bad it is out here."
"We surf fish this every day," added Tim Isaacs. "We know when it's good and when it's dangerous."
Those who spent much of the day on the beach searching and watching still held out hope as the sun went down, as the hours passed a happy outcome became all the less likely.
Report a typo to the ABC13 staff