Would you jump into shark-invested waters to save your best friend’s life? Would you brave the bloody waves to rescue a complete stranger? “Shark Attack Rescuers” (8 p.m., Discovery) documents the incredible and selfless heroism of beach-goers, surfers and professional rescue personnel who have risked certain danger to save shark-bite victims.

Some beaches in Hawaii, Australia and Florida have shark rescue task forces that are ready on a minute’s notice to pluck a wounded victim from the water for transport by helicopter to a nearby emergency room. “Shark Attack” presents interviews with members of these paramedic units as well as amateur shark heroes, including a 12-year-old who saved his brother’s life. “Shark Attack Rescuers” is part of “Shark Week,” Discovery Channel’s annual summer celebration of these ferocious fish.

On tonight’s repeat of “Will & Grace” (8 p.m., NBC) Grace finds herself less than overwhelmed by Nathan’s impromptu proposal. “Cheers” star Woody Harrelson’s turn as the free-spirited Nathan disappointed many fans who worried the show was becoming more about stunt-casting than good writing.

Well fans, look for more stunt casting for “Will & Grace.” Last week NBC announced that crooner Harry Connick Jr. will appear in several episodes as Grace’s new love interest. Connick will play the mysterious horseman who came to Grace’s rescue in last season’s finale. Connick is no stranger to television stints. He guest starred on “Cheers” some years back. While undeniably talented and handsome, one wonders about Connick’s abilities as a comedian. He turned in a less-than-enchanting performance in the recent television revival of “South Pacific” starring Glenn Close.

Kevin Bacon will also guest star on “Will & Grace,” playing himself in the second episode of the comedy’s fifth season. An excited Jack (Sean Hayes) will enthusiastically shadow the star until Bacon hires him as his personal assistant. Jack’s first assignment is to find the nut who is stalking Kevin Bacon! Now that sounds like a cameo worth catching.

Tonight’s other highlights

TNT presents six hours of the PGA Championship Tournament beginning at 1 p.m., followed by the 1996 golf comedy “Tin Cup” (7 p.m.) starring Kevin Costner and Rene Russo.

A computer warns a novelist about his haunted environment on “Beyond Belief: Fact or Fiction” (7 p.m., Fox)

Whoopi Goldberg stars as Wall Street executive in the 1996 comedy “The Associate” (7 p.m., ABC).