Cape Town - The fog appears to be lifting from the Atlantic Ocean, shortly before Matt Silver-Vallance attempts to float from Robben Island to the mainland, near Cape Town on Saturday.
Lift-off is expected shortly after weather conditions improve.
Helium balloons, which will be used as the adventurer's transport, were inflated by a team of 25 since the early hours of the morning for the unique challenge.
It forms part of a campaign to raise R10-million for the building of the Nelson Mandela Children's hospital.
The sun has peaked through the fog, which will make it easier for media and other spectators to view the voyage.
If the fog lifts enough, journalists and other spectators aboard the navy vessel SAS Mhloti will see Silver-Vallance's take-off and follow his trajectory from the Island to Blouberg.
South-African-born Silver-Vallance, who currently works in the medical industry in the UK, will use 200 helium filled balloons to try and pull off his mission.
On one of his earlier twitter posts, Silver-Valance said: “These ain't your Spur balloons, kids.”
The balloons are 15 meters in diameter, which organisers say are 12 storeys high.
Silver-Vallance's flying time from the Island to the mainland shore at Bloubergstrand is expected to last somewhere between 45 minutes and an hour.
Earlier, he was waiting for the wind speed to pick up and change direction.
The ideal wind should be blowing in a north-westerly direction, but was blowing north earlier. - Sapa