Dan:
I am not sure this will be helpful. I have two grounding plates on my commander. One on either side of the keel between the stringers in the engine room. There is also a flat, woven grounding cable bolted down to one of the bolts that come through the hull on each of the grounding plates. All you will see are the 4 bolts sticking up through the hull with this flat cable attached to one of them. Ususally on most of the boats I have seen, they are very close to the area near the engines. You may have to look under your engine also.
Jerry