### Clue: Sound in the Orkneys? It's pervaded by beat, loud and deep (5,4)
### Answer: SCAPA FLOW 
 ### Explanation: Definition: Sound in the Orkneys
CAP (to exceed or beat) in SA (sex appeal, "it") + F (loud) + LOW (deep). Scapa Flow was a naval base in World Wars 1 and 2.