Funny quirk with a new installation of 2.28.1 on Linux Mint under Wine - Sailwave complained that the ratings folder does not exist (under Program Files) . Exploring via Nautilus, I found that was true, but this folder was there in c:\users\Public\Documents\Sailwave, with the RYAPN.csv file.
Copying the folder across to Program Files made SW happy. I could also have just changed the link in Global options to point to the Documents folder, instead.
Rondevlei, South Africa