HAVANA – Endurance athlete Diana Nyad forged ahead through the Straits of Florida with renewed vigor Sunday in pursuit of a record 103-mile, unassisted swim in open waters without the aid of a shark cage.

The 62-year-old Los Angeles woman was said to be comfortable, confident and steady at 50 strokes a minute after a harrowing night of painful jellyfish encounters – despite an improved bodysuit that she had hoped would offer better protection.

Nyad was stung four times during the night on the neck, lips, hand and forehead, according to members of her 50-member crew who updated fans through social media.

“Today is more like swimming,” a member quoted her as saying, on Twitter. “I don’t know what you would call last night ... probably surviving.”

Sunday evening, about 26 hours into the swim, Nyad had traveled 27.7 miles. Video posted on her website showed her on a break joking with the crew, singing a verse from the Beatles’ “No Reply” and asking about a kayaker’s son while sucking nourishment from a long tube.

Nyad, who turns 63 Wednesday, is making her third attempt at a cage-less crossing of the Straits of Florida. She also made a failed try with a cage in 1978.