When you want to use your equipment to help you fish an unknown wreck or featureyou should enter the co-ordinates onto the GPS or use the cursor to align with where the latitude and longditude of your given map dictates. You should now hve a course and a distance to run. As you approach the given target you should then use your zoom facility to keep the mark in question on the screen.
When you have steamed to your chosen location zoom in close to the mark on the GPS. Turn on your Fish Finder and select the 50 khrtz option which is good for searching over a large area. At a slow speed you should pass over the area you beleive the feature to be in. Repeat this process from all the points of the compass until the wreck or rock mark begins to show on the fish finder. When you find it, switch to the 200 khrtz option which is the narrow beam used for precision finding. Now relocate the wreck again with the same process as before. Now when you find it mark it on your GPS.
Now that you have found the feature it is time to map it. Again approach the feature from north to east. Then south to north followed by west to east etc. Each time you see the feature begin to apear on the fishfinder screen mark it on the GPS and when you see it begin to die away again mark it again. When done from all directions you should have litterally drawn a map of the feature and now have a very good idea of how it looks on the sea bed.
If you do this in a detailed fashion you should be left with a perfect picture. Now go back and delete any miss placed marks but be carefull not to delete the wrong ones.
You can now further customise your map of the feature by filling in the highest points of the feature or any other debris that might be lying in the area.