I visited 4 Gatos last year and it was a similar story. One was in the Atlantic, flaky rust, pretty much just a matter of time before she is gone. I think she rests on concrete pillars under the water, so she may not sink, but she might be unvisitable in a few years. 2 were in great shape, but are in fresh water. 1 was in good shape, but is maintained by Navu help, and they have relaced the wood deck with steel tubing that is about the same size and looks roughly like wood.
I guess the best way is a museum building like U 505. But BIG money