According to local lore, Portuguese travelers as far back as the late 19th century suspected that oil might lie beneath parts of East Africa after noticing a thick, greasy sediment wash up on the shores of Mozambique. More interested in finding cheap labor, though, the explorers had little use for oil.

A century later, it turns out that the Portuguese were right. Seismic tests over the past 50 years have shown that countries up the coast of East Africa have natural gas in abundance. Early data compiled by industry consultants also suggest the presence of massive offshore oil deposits. Those finds have spurred oil explorers to start dropping more wells in East Africa, a region they say is an oil and gas bonanza just waiting to be tapped, one of the last great frontiers in the hunt for hydrocarbons. "I and a lot of other people in oil companies working in East Africa have long been convinced that it's the last real high-potential area in the world that hasn't been fully explored," says Richard Schmitt, chief executive of Black Marlin Energy, a Dubai-based East Africa oil prospector. "It seems, for a variety of geopolitical reasons, that more than anything else, it's been neglected over the last several decades. Most of those barriers are currently being lowered or [have] disappeared altogether."

Few have wanted to pay the cost of searching for oil or gas in the region, or risk drilling wells in volatile countries such as Uganda, Mozambique or Somalia. But better technology, lower risk in some of the countries and higher oil prices in recent years have changed the equation. Wildcatters and majors such as Italy's Eni, Petronas of Malaysia and China National Offshore Oil Corporation (CNOOC) have all moved on East Africa in the past few years.