### Clue: Navigational device – there – surrounded by a flashing light (9)
### Answer: ASTROLABE 
 ### Explanation: Definition: Navigational device
 LA(a form of "lo!"/"oh look!"/"there!", as in "La! What a beauty!") **containing**(surrounded by) [A + STROBE(short for a stroboscope/a flashing light) ].
Defn: …, in use before being replaced by the sextant.