Apperently the spool has the same problem as the ci4 when used in salt. It will start corroding. According to shimano.

Hi al, I contacted Shimano asking if the new Chronarch MGL is salt approved. They told me no and that it has similar spool corrosion problems like the previous ci4 when used in salt. Can anyone confirm this?

I created an account just for this question, I have been wondering too wondering if the medium action will go good with my chronarch 51e.