There are 26 11-letter words that start with 'sur'.
Note: These 26 11-letter words that start with 'sur' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with surf, surp, surr, surv, surc, surg, sure, surm, surt, surl, surn, sura, suri, surb, surj, surd.
4-letter words start with 'sur' (4)