I love it: "floating ground" on a boat. That is indeed hard to get your head around.
Yeah, I like it too...

A mate of mine actually built the boat and he and I and another mate who had shipwright experience discussed the grounding issue.
I thought it might be a good idea to have a metallic connection into the water as part of the boats ground but apparently that can cause some serious electrolysis problems so the idea was canned.