Not many people know it but could be interesting and useful to many. Think at the end would enter in the How To section. So here the task.

You are on the shore looking at lets say an Oil Platform:

800px Cromarty Oil Platform

and you are wondering how to determine its coordinates? By chance you have a Garmin handheld with you. So how are you going to determine its coordinates? Approximately of course.

Regards,
DD