This song is not originally by Mono Puff. It was originally a Clamdiggers song written by Nat Freedberg (aka Lord Bendover) and Ted Widmer (aka Lord Rockingham). The full name of the Mono Puff version of the song (and possibly the Clamdiggers original) is "The Devil Went Down To Newport (Totally Rocking)". In addition to appearing on the album Unsupervised (1996), it was also the title track on The Devil Went Down To Newport (Totally Rocking) EP (1996).
The song is possibly a parody of or tribute to Devil Went Down To Georgia by the Charlie Daniels Band. There are similarities between the two songs. In Devil Went Down To Georgia, the devil challenges a young man to a fiddling competition. In this song, the devil competes in a surfing competition, although it is against the Lord, not a mortal. As well, In Devil Went Down To Georgia, the young man defeats the devil. Although it isn't entirely clear, it does appear that the devil loses the surfing competition also.
Finally, it should be noted that Newport probably refers to Newport Beach, California rather than Newport, Rhode Island. Although the Clamdiggers were a New England band, Newport Beach in California is well-known for surfing. Newport, Virginia and Newport, Oregon are both unlikely also.