small system grounding question
I have done a search, and haven't found a good answer, or at least one that is concise enough for me to under stand so I'll start a new thread.
We live on a small island in the middle (really the middle!) of a big lake on the Canadian shield. The entire island is almost bare rock, with little soil. The current grounding system(s) is this: Each generator frame, neutral ground, building ground etc carry a ground wire out the building, along the rock, and then into the lake.
In conversation with someone on another site, on another matter, it was suggested that this was a very dangerous situation. In the event of a strike in the lake,(a common event!) the energy could pass back up the ground wire and energize the system. We have never had any trouble in 60+ years of using this system.
My question is, is this system safe, or are there alternatives that I could explore. I cannot drive ground rods anywhere. My intuition is that any strike near enough to the ground wires (in the lake) would dissipate it's energy into the water so that the potential current would be very limited. I have had a ground wire struck once before. Lightning wrapped it's way down a tree, ran along the ground until it found the wire. It energized the system and blew out the charge controller as well as a 12vdc radio that was hard wired to the system. Other than that there was no damage.
I'm fairly confident that the gensets, and the inverters are safe (for protection from short circuit and shock) but the lightning question is now unclear. Any and all opinions would be appreciated.
Please note, being a moderator does not add any weight to my opinions 300 watts Siemens/BP panels,plus a Sun 90,, making ~400. ~30 amps into Rogue MPT-3024, 450 ah of Trojan T-105, Morningstar ts300 inverter, a Tri-Metric meter.a collection of antique generators, plus 2 Honda eu-1000i's (also a BS2512 IX controller) and assorted other stuff!