Further complicating matters is the camera crew following Wood to shoot a four-part documentary series for U.K. and U.S. audiences on Britain's Channel 4 and America's Animal Planet. Wood and his crew were arrested while filming near the only bridge that crosses the Nile in South Sudan.
Weaving through the chaotic traffic in Juba, South Sudan's capital, Wood and his crew set a blistering pace. Their South Sudanese guide occasionally barks orders to stop filming near a national memorial or military installation.
There are safety concerns for this leg of the trip. The Nile passes through Jonglei state, a region that has seen heavy fighting in recent months.
"As that's the front line, I'll have to make a decision when I get there whether I have to move away from the river," he said.
Then, a well-known Juba curiosity strolls past: a lanky man who is totally naked.
The team laughs. "No comment," Wood says to his probing cameraman.
While South Sudan appears to be the toughest part of his trip, it was in Uganda where tragedy struck. Experienced American adventure journalist Matt Power, who was walking with Wood, died from heat exhaustion March 10. Wood said the death forced him to reconsider his plans.
"We took a week off just to contemplate what happened and have a think about, 'Is this something we really want to be doing?,'" he said.
After speaking with Power's wife and family, Wood, with their blessing, decided to continue.
"It is one of those things that really brings home the reality that this is not an easy thing to do. It's incredibly difficult and dangerous in parts and all I can do is be as prepared as I can be and hope the same doesn't happen to me," he said.