It’s taken 10 years and 227 episodes, but Harm and Mac finally get around to owning up to their feelings for each other on tonight’s “JAG” (8 p.m., CBS) series finale. “JAG” debuted in 1995 and was long the only network drama to unfold against a military background. Some found that odd, given that during the past ten years, an increasing number of American soldiers and reservists have been deployed in harm’s way in the Balkans, Afghanistan and Iraq.

“JAG” was also a TV rarity: a show that was developed and cancelled by one network (NBC, 1995-96) only to become a hit on another network (CBS, 1996-2005). In recent years, we’ve seen other network migrations. “Grounded for Life” went from Fox to the WB. “Family Guy” has wandered from Fox to Cartoon Network, only to return to Fox this Sunday. Arguably, the best show to appear on two different networks was “Taxi.” “Taxi” began its ride on ABC in 1978, but they dropped the low-rated comedy in 1982. NBC picked it up and ran it for four more seasons, but the ratings never improved much.

Tonight’s other highlights

• Russell Crowe stars in the 2003 adaptation of “Master and Commander: The Far Side of the World” (6:30 p.m., HBO), based on the popular series of nautical novels by Patrick O’Brien.
• A horse trainer is trampled aboard a plane on “CSI” (7 p.m., CBS).