Nav Computer: Centre dot on TAS (375
kts), rotate to put wind direction (130ºT) on HEADING index and mark wind on
centre line 55kts below centre dot (over 320 kts). Rotate to put heading 124ºT
next to HEADING index; read drift and groundspeed under wind mark: 1º Port
(left) (track 123ºT) and 320 kts.