WORTH NOTING ON TV

* TUESDAY

House of Representatives (C-Span, noon to conclusion, EDT): The channel's regular live coverage. * WEDNESDAY

National Geographic Special (PBS, 8-9 p.m.): Broadcasters tend to assume that viewers never tire of colorful undersea photography - and they're probably right. ``Jewels of the Caribbean Sea,'' by the husband-and-wife filmmaking team of Howard and Michele Hall, offers views of marine life from the Cayman Islands, the Bahamas, the Virgin Islands, Dominica, and Belize.

That may sound like familiar stuff, but Howard and his diving partner, Bob Cranston, are using an apparatus with the rather unappealing name ``mixed gas rebreather.'' The device is considered dangerous to divers, but it has the advantage of letting them stay underwater for extended periods, and it emits no air bubbles. Divers can thus remain relatively unobtrusive to sea life and get some unusual footage.

Coral reefs are the site of much of the action, where mating habits and other parts of the life cycle are caught on camera. Spiny lobsters walk across the sea floor, squid flourish a blaze of color to ward off predators - the drama is exotic and the scenes are eye-filling.

The Mao Years: 1949-1976 (PBS, 9-11 p.m.): Just after the Tiananmen Square massacre of 1989, PBS aired an award-winning documentary called ``China in Revolution, 1911-1949,'' which examined the foundations of modern China. This new program picks up where the first left off, studying a period in Chinese history dominated by its leader, Mao Zedong. New footage of Mao, Deng Xiaoping, and other Chinese leaders provide an unusually intimate look at their private and public lives - like a private dance for privileged officials. Interviews, archival clips, and other carefully selected tidbits document important events - the Great Leap Forward, the Cultural Revolution, the ground-breaking visit by President Nixon. The film gives point to these events - some of them tragic in their impact - through a focus on stories by people who lived through them.

Please check local listings for these programs.