We're kind of point A to point B people at Shmoop. Give us a nice four-wheel drive and a good stretch of highway—or, better yet, an airplane with a loaded iPad.
But not Huck and Jim. Their vehicle of choice is a raft: something that can barely be steered and that only goes as fast as the river it's on. But the raft ends up being a kind of no-man's land that seems to operate under different laws than solid ground. In a way, it provides a space for Huck and Jim to get to know each other man-to-man rather than master-to-slave. As Huck says, "we… let her [the raft] float wherever the current wanted her to; then we lit the pipes, and dangled our legs in the water, and talked about all kinds of things—we was always naked, day and night, whenever the mosquitoes would let us" (19.4).
Floating down the middle of the river (and naked) just might be the only place this black man and white boy can speak together as equals. And that makes it a pretty important symbol.