Do you fill out the width of the Indy or is there space? I know a lot of TTS D-widths could use a C-width in the Indy.
Also, I had a type-o as I am a TTS 11E.
My chamois shoes are great in the wet, so the boots would be even better. The heavily oiled leather also is good at resisting salt intrusion. I posted about sealing mine several pages back.