Another thing that Sirius does that a lot of people aren't talking about is their data services. Having updated weather and fish maps live while you're offshore is pretty handy and satellite internet connections can be very pricey.
This is stuff like fishing recommendations by species, sea surface heights, temperature contors, 30m deep temperature condors, plankton concentrations, weather radar, storm tracks, wave heights, and more and then integrated into common Garmin, Raymarine, Lowrance, Simrad, and other equipment that many boats would already have. All of that data constantly updated and refreshed live even when you're miles out to sea and can't pick up common line of sight style transmissions.
Its not just a METAR weather report from an airport kinda near the shore.