surf (n.) Look up surf at Dictionary.com
1680s, probably from earlier suffe (1590s), of uncertain origin. Originally used in reference to the coast of India, hence perhaps of Indic origin. Or perhaps a phonetic respelling of sough, which meant "a rushing sound."
surf (v.) Look up surf at Dictionary.com
"ride the crest of a wave," 1917, from surf (n.). Related: Surfed; surfing. In the Internet sense, first recorded 1993.