It's an energetic piece of music, where some "general rules" within Reggae Music are stretched beyond their usual realm. And this goes especially for the drums.

Usually, the drums in Reggae music emphasize the 3rd count, where the piano and guitar play their chords on the 2nd and 4th beat. 

In this tune, the drums play on the 2nd and 4th as well. The result is an up-tempo feel without an actual high speed.

Originally, this particular drum rhythm is used by the one and only Sly Dunbar. For example, on a tune called "Don't Look Back" by Peter Tosh and one other singer called Mikey Jagger.