Nature: Ocean Giants (8pm, UNC-TV) - A three-hour special on the underwater world of whales and dolphins. Included, the human-like qualities of the animals and their reliance on sound underwater.
American Idol (8pm, Fox) - Contestants have one last chance to win over the judges before the first group of semifinalists are revealed.
Raising Renee (8pm, HBO) - NCCU professor Beverly McIver tells her story of caring for her mentally disabled sister. Adrienne's review.
Modern Family (9pm, ABC) - Gloria learns a secret that Claire has been hiding, and one of Jay's proudest golf moments is ruined by Mitchell.
Happy Endings (9:30pm, ABC) - The end of winter signals "Spring Smackdown," when Jane (Eliza Coupe, right) and Brad (Damon Wayans Jr., right) have their annual domestic dispute.
Royal Pains (10pm, USA) - Hank struggles to accept Jack's illness in the Season 3 finale, and Evan joins Boris' cousin to look into an experimental treatment.
American Weed (10pm, National Geographic Channel) - A new short series that takes an in-depth look at Colorado's medical marijuana industry. Tonight's episode profiles Fort Collins dispensary owners who face the possibility of having their businesses shut down should voters approve Proposition 300.
CSI (10pm, CBS) - The CSIs investigate when a house is stolen from its foundation. Also, Julie displays her skills in blood analysis.
Note: No new "Revenge" tonight.