Maroney is assisted to shore in Cuba

In this story:

• 123 miles across Yucatan Straits
• Maroney 'in good health'
• Intended to swim 145 miles

HAVANA (CNN) - Australian marathon swimmer Susie Maroney overcame choppy seas, stinging jellyfish and uncooperative bureaucrats to set what organizers say is a world record for an unassisted distance swim in open water.

"I am just so sore and so glad it's finally over!" said the exhausted 23-year-old after staggering up Las Tumbas beach in darkness at 5:03 a.m. Monday.

Maroney spent 38 hours and 33 minutes in the shark- and jellyfish-infested waters to become the first person to swim an estimated 123 miles across the Yucatan Straits. She left Isla Mujeres, Mexico, at 2:30 p.m. Saturday.

CNN's Lucia Newman reports 2 min. VXtreme video

Watch as Maroney comes ashore 2.6MB/50 sec./240x180 1.7MB/50 sec./160x120 QuickTime movie

Maroney made most of the crossing in a cage designed to protect her from sharks. But as she left the cage and swam the last stretch toward the remote cove at Cuba's western end in darkness, her brothers swam with her to protect her from sharks.

When her feet touched the sandy bottom, she let out a muffled cry of pain and relief.

Cuban officials, international journalists and members of her support team -- waiting on the remote Caribbean beach -- burst into applause, and organizers sent the news out to the world by satellite telephone.

Maroney swims surrounded by a shark cage

Breathless and barely able to carry her own weight, Maroney had to be helped out of the water by her brothers. She winced in pain at the jellyfish stings which a special Lycra swimsuit and the shark cage failed to prevent.

But there was no hiding her joy.

"Now I'm all sore and everything, but it's just the best feeling when you hit land and you see your family's faces and they're so proud of you," said Maroney, her own face a mixture of physical pain and mental delight.

A doctor examined Maroney, and event coordinator Joe Pignatiello told Reuters by telephone: "She's in good health."

Asked what the worst part was, she said, "Definitely the night. That was the worst bit."

"The waves were just so much bigger than last time," said Maroney, who last year became the first person to swim across the Florida Straits from Cuba to Florida, a journey of 108 miles (173 km). "I swallowed so much water. It was really bad."

"The first night, the seas were very rough," said Dr. Michael Smith, Maroney's physician. "She had quite a bit of seasickness and some vomiting, so we reduced her to small sips of liquids every hour and small bits of baby food."

But Maroney also said that "as soon as I got through the night, I knew that I would be OK. If I'd gone that far, I wouldn't quit."

Maroney reached Las Tumbas after being obliged to swim several extra miles along the coast when Cuban authorities refused to allow her to come ashore at a lighthouse at Cabo de San Antonio and recommended she continue to the beach.

She was also forced to begin her swim a day late when Mexican authorities insist she sign a waiver absolving them of any responsibility should something go wrong.

Maroney prepared for her ordeal on a diet of baby foods, marshmallows and custard, and originally intended to swim 145 miles (233 km) from Isla Mujeres to Maria La Gorda in Cuba.

But as she neared Cuba's western tip, the Cape of San Antonio, late Sunday, she decided to shorten the final part of the swim and come ashore.

Rough seas during the early part of the trip partly damaged her sharkproof cage, and a hole in the mesh of the cage was patched with a net. Her crew had been especially worried about the danger from sharks when Maroney left the cage at the end of the swim to reach the shore.

After a brief stop on Las Tumbas beach, Maroney boarded her support boat and headed for the Cuban capital of Havana.

Asked what new challenges lay ahead, the swimmer said she wanted to rest in Cuba a couple of days first. Then, she said, "There's always something that I want to do, but I can't think of it just now."