![cheap sunglasses :cheap-sunglasses](./images/smilies/smiling-face-with-sunglasses.png)
https://youtu.be/4fDcnZUmpUk
I think being in and out of salt water, so also being exposed to air, causes corrosion quicker than just being fully submerged. Rust is an oxidation reaction. With that said even fully submerged, if it can rust it will.
I too will be watching this thread intently. I just wish you had a MULE model in both edge types to test. But SE can be determined at a later date with no problem.