At one point in the last year there were three ships in Tauranga harbour, they were the Voyager of the Seas which held 3000 people, the Seven Seas Mariner with 700 people on board and Seaborne Odyssey with 462. These three ships were investigated by the international Friends of the Earth network, they found that all three failed the environmental assessment they established. Royal Caribbean International had an A for wastewater and water quality, but an F for air pollution. The same goes for The Seaborne Odyssey, but Regent Seven Seas Cruises is the worst with a C+ for wastewater, an A for water quality and again an F for air pollution. The F means they have failed to cooperate with Friends of the Earth processes. Having all three Tauranga cruises running for a day or two would have had a negative impact on Tauranga's clean air, the average cruise ship produces more sulfur dioxide than 13 million cars. To solve this problem, Friends of the Earth is influencing people to choose their cruise after examining the environmental effects. Right now, Carnival cruises have the best environmental rating. To limit air pollution in New Zealand ports, more and more cruises are choosing to use offshore energy