A federal appeals court on Friday said the U.S. Navy could use high-power sonar during exercises off the Southern California coast despite the technology's threat to whales and other marine mammals.

A majority on a three-judge panel of the 9th Circuit U.S. Court of Appeals said the Navy can use the high-power sonar in 11 planned training exercises in its reversal of a lower-court order banning the practice.

Judge Andrew Kleinfeld, writing for the majority, said national security interests outweigh the possible harm to marine life.

• Click here to visit FOXNews.com's Natural Science Center.

"The public does indeed have a very considerable interest in preserving our natural environment and especially relatively scarce whales," Kleinfeld wrote. "But it also has an interest in national defense. We are currently engaged in war, in two countries."

Judge Milan Smith Jr. disagreed with his colleagues on the panel and said he would have kept the ban in place. Smith said that the lawsuit filed by Natural Resources Defense Council to stop the use of sonar is likely to win.

Smith said the Navy was free to use the sonar outside of Southern California waters.