After 10 seasons of submarine silliness, “SpongeBob Squarepants” (7 p.m., Nickelodeon) can do anything his porous heart desires. Including, it seems, landing one of the planet’s top movie stars.

The voice of Johnny Depp appears in tonight’s episode as Jack Kahuna Laguna, or JKL for short. He’s a legendary mystic surfer who teaches Spongebob, Squidward and Patrick how to ride “The Big One,” a giant wave big enough to take them home after being washed out to the haunted waters of the Dutchman’s Triangle. Depp’s surf guru seems modeled on Patrick Swayze’s character Bodi from the 1991 thriller “Point Break.” He also seems inspired by Marlon Brando’s bongo-playing persona from his early 1950s heyday. Who better than Depp to channel that brand of nonsensical grooviness?

It’s also nice to see that a solid decade of popularity hasn’t affected this cartoon’s cracked sense of logic. The episode begins with a heat wave, features a trip to the beach, surfing lessons and a helicopter ride, all taking place below the waves.

And let’s not even think about the penny-pinching Mr. Krabs, who appears to make his living selling crab sandwiches.

Depp is not the only pop icon to grace this episode. Look for a certain singing TV star from days gone by, hiding out in an undersea locker that bears his name.

• “Prison Break” (8 p.m., Fox) returns with Michael and Sarah using their thumbs to attract riders and Lincoln getting the low-down from Christina. This marks the final season, or half-season, for “Prison.” It will wrap up with a two-hour season finale on May 15. A repeat “Prison Break” (7 p.m.) also airs. “Dollhouse” returns next week.

• When a 13-year-old vanished from a Detroit area Dairy Queen in 1986, the police considered it a case of a runaway teen. A two-hour “Dateline” (8 p.m., NBC) profiles the detective who picked up the case and its cold trail six years later and who, after more than 23 years, can finally bring the family of Cindy Zarzycki some answers.

• Turner Classic Movies continues its 15th birthday celebration by allowing fans to program their movies, including favorites like “The Maltese Falcon” (7 p.m., TCM).

I’d like to meet the programmer who chose the obscure “Summer of ’63” (4:30 a.m.), a cautionary tale from 1972. Michael Bell narrates the film as a grown-up doctor recalling a season of youthful indiscretion that spread disease and shame amongst his circle of friends.

You have to admire a network like TCM. It’s confident enough of its mission and direction to broadcast both quality films and fascinating oddities like “Summer.” Now that’s what I call class.

Tonight’s other highlights

• On two episodes of “Patton 360” (History), the invasion of North Africa (7 p.m.), Victory over Rommel (8 p.m.).

• Katie can’t sort out her feelings for Jack on “Mistresses” (8 p.m., BBC America).

• Video footage and dramatic re-enactments recount dangerous encounters with animals and men on “Untamed Alaska” (8 p.m., Discovery).

• Henry Winkler guest stars as an FBI agent in pursuit of con men on “Numb3rs” (9 p.m., CBS).

• Scheduled on “20/20” (9 p.m., ABC): an interview with Monica Seles about tennis, surviving an attack and her father’s death.