These are the centerpieces of a burgeoning energy boom that's transforming East Africa into a vast source of oil and gas for energy-hungry Asia 3,000 miles away across the Indian Ocean.
"You have almost an embarrassment of riches in Mozambique and Tanzania, in terms of the volumes of gas being discovered," said Philip Wolfe of UBS financial services, which advises Thailand's PTT Exploration and Production, now a major player in Mozambique.
"In Mozambique, they've only just scratched the surface and have already found so much gas."
After about two years' exploration, around 100 trillion cubic feet of natural gas has been found in the Indian Ocean off the former Portuguese colony and Tanzania.
That's equivalent to nearly all of Iraq's gas reserves.
The Rovuma Basin holds most of the newfound gas, with 80 tcf in Mozambique's waters and 20 tcf off Tanzania to the north.
Tanzania's prospects improved Wednesday when Britain's BG Group, a major energy multinational and the largest supplier of liquefied natural gas to the United States, announced new gas finds in blocks close to Mozambican waters.
BG Group and its U.K.-listed partner Ophir Energy said gas flows from a new well in the Mzia-2 field "significantly exceeded our expectations."
Ophir increased its estimate of recoverable gas there by around 25 percent, from 3.5 tcf to 4.5 tcf.
The pair plans to move exploration north toward a zone held by Statoil of Norway which the Financial Times said "could extend the scale of recoverable resources estimated for other discoveries and prospects off Tanzania that are calculated at 4.1 tcf."
Statoil said in March it had found 4-6 tcf 60 miles of the Tanzanian coast, raising the recoverable reserves there to 10-13 tcf.
These companies are already seeking sites for LNG terminals on the coast to feed gas to the Asian markets.
The Financial Times said Statoil and BG Group are planning a two-train liquefaction plant for an initial $14 billion investment, and adding to that if further fields are found.
The U.S. company Anadarko Petroleum Corp. and Eni of Italy, which have made major strikes off northern Mozambique, are mulling plans to cooperate on developing other LNG plants with investment totaling $50 billion.
This investment is heavy, but the Asia-bound LNG shipments from East Africa will have a major advantage: they won't have to transit the strategic Strait of Hormuz.
That's the only outlet from the Persian Gulf into the Indian Ocean and Iran has threatened to shut the narrow waterway if it's attacked over its nuclear program.
That would cut off most of Asia's gas imports from the Middle East.
ENI, a major player in the region, said April 25 it had raised its estimate of reserves in its Area 4 block in the Rovuma Basin from 75 tcf to 80 tcf.
Underlining the growing international interest in East Africa, ENI said in March it had agreed to sell a 20 percent stake in its giant Mozambican fields to China National Petroleum Corp. for $4.21 billion.
The Chinese, who're expected to be importing 35 percent of their gas by 2015, have spent an estimated $10 billion buying 93 oil and gas assets since early 2008.
Beijing's focusing on Africa now and has spent more than $6 billion acquiring oil and gas resources in Angola, Uganda and Nigeria since 2010 to meet China's swelling energy requirements.
But East Africa has sizeable oil reserves as well.
Kenya's Great Rift Valley, a 450-mile long volcanic trench that's part of a 3,700-mile system that runs from northern Syrian to Mozambique, could contain 10 billion barrels of oil.
Uganda's expected to start producing soon from reserves of 3.5 billion barrels discovered in the Lake Albert region in 2006. Kenyan production's not expected until 2017.
Tullow from the United Kingdom, Total of France and China National Offshore Oil Co. are looking at plans for an export pipeline from Lake Albert to the Kenyan coast.
The Democratic Republic of Congo's thinking of joining in. South Sudan's also seeking an export outlet via Port Lamu in Kenya, and that country could end up being a key export hub for the region.