HAVANA (AP) -- Endurance swimmer Diana Nyad has more than passed the 28-hour mark of her attempt to swim a record 103 miles in the Straits of Florida.

It was a rough night for the 62-year-old on Saturday, when her crew says she was stung by jellyfish four times.

This is Nyad's third attempt since last summer at a cage-less crossing.

According to her support team, Nyad has been doing the backstroke. She's swimming that way so that the part of her head that is covered by a cap is in front -- in hopes of reducing contact with jellyfish. And a tweet from a team member says "the backstroke is working!" The team reports that she is steadily stroking onward. 

An apparatus that is following her in the water creates a faint electric field that is designed to repel most sharks.

Last summer, an asthma attack and then jellyfish stings forced her to abandon two attempts.

Associated Press