Special Isn’t Always at Its ‘Best’

National Geographic’s “Explorer” series goes to the ends of the Earth to track down stories, but in its “Best of 2001” special (5 p.m., MSNBC), sometimes it just doesn’t go far enough.

The curious lack of follow-through is present in only a few of the brisk segments, but it’s enough to bring the show’s considerable “wow” factor down a notch.

For example, there’s the story of an Arkansas town being terrorized by sightings of a huge anaconda. A renowned snake expert is summoned to rid the good citizens of the critter, but after we catch just the briefest of glimpses of what may have been the anaconda, it slips into a river. End of segment.

Then there’s the effort to raise one of the world’s first submarines from the sea floor off South Carolina. The Confederate vessel went down with all crew aboard during the Civil War, and a team of engineers is convened to devise a way to lift the craft to the surface intact, so as to preserve whatever might be in it.

Well, the sub is raised, all right, but the segment ends with nary a peek inside.

The show’s at its best when, as one person put it, “observing nature takes a back seat to surviving it.” There’s a harrowing segment in which researchers charting the effects of the moon on volcanic eruptions manage to get gas masks on just before radically shifting winds push the volcano’s poison gases back toward them.

The photography here and throughout is, as one would expect of National Geographic, world-class.

And chimp champ Jane Goodall is caught in an interesting moment of reflection after seeing how jungle clearing by villagers desperate for farmland is affecting her precious primates. Segment producer David Hamlin says Goodall has come to the realization that “to save the chimpanzees, she has to save the people.”