CANBERRA - Breathing air provided by algae watered with recycled urine, and pedalling a bike for electricity, an Australian aquanaut emerged on Wednesday after 13 days living underwater in a "biosub".
Lloyd Godson entered the 2 metre-high yellow biosub capsule, submerged in a former quarry on wetlands nearthe southeastern town of Albury, on April 5.
His survival at a depth of 5 metres hinged on a coil of green algae which provided air in return for Godson urinating on the plants each day.
"I will be glad to get out in the sunshine and fresh air again. I have even had thoughts of running like Forest Gump, and just not stopping!" Godson told Reuters before surfacing.
Godson, 29, a marine biologist, got funding for the project after winning a "Wildest Adventure" competition run by nature journal Australian Geographic.
Godson's partner and support crew member Carolina Sarasiti said he was not trying to break any underwater records. "It's more of an experiment to use a few scientific concepts. He wanted to live his dream, which was to live underwater," she said.
A team of divers provided meals to the capsule through a manhole in its base, while some electricity came from the bike and some through a bank of onshore solar cells.
A single daily blast of fresh air was also provided from above, after trial and error with levels provided by the algae "biocoil", Sarasiti said.
"It's never been done before using air from the plants," she said, adding the experiment had been designed to prove whether an underwater environment could be self-sustaining.
Entertainment in the two-metre by three-metre capsule came from a drum kit which Godson could use at all hours without upsetting neighbours other than fish.
Godson's underwater sojourn has been followed by schoolchildren from across the world on his biosub.com.au website. His physical and psychological state was measured daily and results sent to the United States for evaluation.
"At times it has been stressful, but more just exhausting from talking all day to (website) visitors and the press. I expected solitude and got the opposite," Godson said.
