After what seemed like an eternity in beta... OK about a year, I'm pleased to announce that Black Cat GMDSS version 1.0.0 is now available for Windows and macOS.
Black Cat GMDSS decodes GMDSS-DSC / Global Maritime Distress and Safety System (GMDSS) / Digital selective calling transmissions. Up to 8 decoders can run at the same time, so you can monitor all the active GMDSS channels at once. Virtual sound cards are supported for interfacing with all the popular SDR programs.
Download a copy here, it's free to try prior to purchase:
https://blackcatsystems.com/software/black_cat_gmdss_decoder.html