I have a 997 c SI. I fish off the coast of Tarpon Springs FL. Generaly I use my standard sonar to look for bottom structure. Then slow down and use side scan to find the rocks and ledges. I then mark a waypoint on the specific area of interest then move to that location, drop a marker bouy and then drop the anchor so as to fish right on the spot.
It is also awesome when you get a number from someone else or from a map of say an artificial reef as you can verify you are in the correct location because you can see the ship or culverts or whatever is on the bottom. As you know Grouper love structure and if you don't see any you do not stop just keep looking. Most of the time a simple zig zag in the area is all that is needed.
Hope this helps