The basics: The safety
ground wire is designed to go from the shore power
inlet to the AC safety
ground bus. All AC loads on the boat have their safety ground wire tied to that same AC safety ground bus. This provides a redundant circuit back to the source, usually a transformer outside of the marina, for fault current
. This redundant path will then trip a circuit breaker should a fault occur. In accordance with ABYC E-11, the vessel B- ground is to be electrically connected to the safety ground bus using a single
I am concerned with your comment: "However the green grounding wire that goes to the boats DC Neg buss is an easy reach."
as, on the surface, it does not appear that your boat is wired in accordance with the basics above.
Since the first thing that your safety green wire "sees" after leaving the shore power inlet is the AC safety ground bus, you can put the GI any where along the conductor.
As far as the different manufacturer's of GI, you will get what you pay for. Either a GI with a monitoring system to ensure the integrity of the safety ground wire or a "fail-safe" are permitted by ABYC A-28. The "fail-safe" models are built of more robust components and are the ones that I recommend. The manufacturer with the most robust units, in my opinion, are those from Dairyland Electrical
Industries: DEI Marine - Products
Hope this helps.