PBS, 9:00 pm ET
Dr. Robert Ballard, celebrated for his undersea explorations, undertakes another mission in the new documentary "Nazi Attack on America" -- largely a study of a U-boat whose wreckage was found submerged off the coast of Louisiana. What is discovered in the remains helps paint a thorough picture of Operation Drumbeat, a concentrated World War II attack by German vessels against American forces over a period of more than three years.
PBS, 8:00 pm ET
Often used as a source of humor for its ability to mimic others -- even James Bond at the end of "For Your Eyes Only" -- a certain bird's more serious aspects are considered in "Parrot Confidential." The program delves into challenges faced by breeders and owners, with some of them candidly discussing why raising parrots is problematic as well as beneficial. Also noted: the role of the television series "Baretta" in parrots' popularity.
FOX, 8:00 pm ET
"Critical" is the word for the episode "Top 3 Perform" -- as the title should indicate -- since what happens in these two hours will determine which two finalists go for the season's title. That much time gives those who remain plenty of opportunity to show why each of them should be the new American Idol, along with lots of space for Harry Connick Jr., Jennifer Lopez and Keith Urban to make their judgments and pronouncements. Ryan Seacrest is the host.