### Clue: Ben's height is measured relative to this Cork daredevil biker (3,5)
### Answer: SEA LEVEL 
 ### Explanation: Definition: Ben's height is measured relative to this
 SEAL(which could be accomplished with a cork, cf. wine in bottles) + EVEL(Knievel, American daredevil biker and stuntman).
Defn: The datum above which the height of a mountain, including any Scottish ben, is measured.