As far as metaphors go, this one doesn't clear the fence.  I guess he was
inspired by the Mississippi river, and the proximity to Hannibal. Maybe
because he seems to be having so much fun, although that would make him more
of a Tom Sawyer.

If Huck played baseball, I can't see him as a power hitter.  Maybe a
reliever.

  I can't picture him playing baseball at all, although I can see Twain in
the announcer's booth.

Terry Ballard