I will need a log from right after you've had the error and the giant boat appeared. :)
I did spot some old mods though that should be removed.
- Ploppable RICO - get Ploppable RICO Revisited instead
- Painter - get Repaint instead
- Pause on load - this is an option in the game, so just remove this mod
- Advanced Toolbar - use More Advanced Toolbar or Resize It instead
- Water Color Changer - honestly not sure about this one, but I know Environment Colors Changer works
- No More Purple Pollution [Brown Water] - use No More Radioactive Desert and more instead
- No More Purple Pollution - use No More Radioactive Desert and more instead
- More Beautification - use Find It instead
Remove those mods, get the replacements and make sure to enable the replacements. Then restart the game and try to load the save with the giant boat problem. Then upload the output log somewhere again and link to it, so I can have another look and hope...
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