More traditional satellite networks, I guess? As I understand it, this is what sailors do / did before starlink.

This had me curious if I could find coverage maps of satellite operators, and I found this: https://www.satphonestore.com/coveragemaps

I'm speculating, but I'm fairly sure that they already have any and every satellite communication system available on-board, just as a back-up. If they're using Star link, it should be because it's working best.

Most sailors didn't (and don't) have reliable internet access.

I’ve absolutely no idea, but wouldn’t a satellite system higher up like Hughes have a better chance of working out there?