Zincs and Bonding

[Flying Knight]

I had the bottom cleaned for the first time since purchase yesterday and was told by the diver that:

1. There were no zincs on the boat - not even a trace on the end of the prop where one would normally be installed.
2. The prop was in great condition despite this.
3. There was something extruding from the hull bow the waterline forward on the port side. He described it as a clear "window" in the hull.

I had him place a zinc on the prop to be sure, but he thought what he saw there might be to prevent electrolysis. I'm dubious, but thought someone might be able to tell me what I'm looking for to verify whether that's what this thing is that he's seeing.

From what he understood there's some type of system that will prevent electrolysis via some method other than traditional bonding with zincs. He mentioned that all my thru hulls might be bonded together on the inside. He couldn't even say what the system would be called, so I'm at a loss as to what to even look for. Can anyone shed some light on this?

[a64pilot]

what did the survey say?

[Flying Knight]

Surveyor didn't mention it. I didn't see it when it was hauled out either.

Sent from my Nexus 5 using Tapatalk

[fstbttms]

You need to find a diver who knows what he's talking about.

[Flying Knight]

Obviously I'm very skeptical, but he says he's seen something like this on larger boats, and then there was the prop with no zinc, not even a trace, but also with no damage.

I guess I'm wondering if anyone has heard of a system like this, that prevents electrolysis via an electrical device attached to the hull and not zincs, and what it would be called so I can try to research and find out if he was right.

Sent from my Nexus 5 using Tapatalk

[fstbttms]

He may be referring to an "impressed current system" although I've never seen one on a fiberglass hull before. But it's your diver's description of a "clear window in the hull" as part of such a system that makes me think this guy doesn't have a clue what he's talking about.