Nav Computer: Centre dot on TAS (290 kts but use the high speed side of the slide), rotate to put wind direction (310ºT) on HEADING index and mark wind on centre line 30kts below centre dot (over 260 kts).   Rotate to put heading 171ºT next to the HEADING index; read the drift and groundspeed under wind mark: 4º left (Port) and 314 kts.