Fly the measured track.... for the estimated time of enroute to your destination....turn into wind...guess/figure the distance you would be off course and Bob's yer Uncle! The only trick was having enough Vis to be able to see your Rig, Platform, or Well Head within the circle of error caused by the wanderings of your heading/airspeed control, deviation in the Compass, and misjudgement of wind speed and angle. At least when you got out into the field you knew which way to turn to find what you were looking for. Otherwise you fetched up in the middle of no where looking at an empty ocean wondering where the rig had run off to and no idea which way to go to find it.
Learned in the old, old, old, days of mag compass, clock/watch/airspeed only for finding yer way around the oggin.
Ah yes.....ILS approaches looking out the side window for the runway!