Per the National Electrical Code, service equipment that has been immersed must be replaced.
Your local codes may vary, so check with your municipal inspector/engineer.
If it was me, I’d go ahead and replace it all, especially if it was immersed in salt water.
Yup. Submersion adds a variable that the UL testing can’t account for. The corrosion and change in dielectric properties may be minute but it’s now considered a risk.
Sucks for the homeowner.