Matt Silver-Vallance gets ready to fly across the sea from Nelson Mandela's apartheid island prison using helium-filled giant party balloons, on April 6, 2013 in Cape Town. (RODGER BOSCH/AFP/Getty Images)

Traveling by balloons might look exciting, but with unpredictable wind conditions it can make for a bumpy ride.

Matt Silver-Vallance floated from Robben Island, where Nelson Mandela was imprisonned for 18 years during apartheid, to the coast of South Africa -- using nothing but 160 helium-filled balloons and a paragliding harness. His goal for the stunt was to raise money for the Nelson Mandela Children's Hospital. The 3.7-mile crossing over the sea took about an hour.

According to Discovery News,Silver-Vallance controlled his flight with heavy bags of water and an air gun and spear to pop balloons. But the wind conditions proved more challenging than he'd anticipated.

"I got to about one thousand feet, about the height of Table Mountain," Silver-Vallance said in an interview with The Mail and Guardian,a national newspaper in South Africa.

He eventually resorted to popping about 35 balloons with a spear so that he could be pulled in by sea rescue vessels.

ABC News reported that the support team that assisted Silver-Vallance from the water helped him "navigate shark-infested water, a nuclear power station and the flight restricted zone near the airport."

The flight came to an end shortly before Silver-Vallance reached the shore, since a water-landing was deemed safer than trying to reach solid ground. The project raised about $10,000 for the Nelson Mandela Children's Hospital.

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