Cruise ships are slowly being outfitted with high speed spot beam internet access. A friend working on RCCL's Quantum Of The Seas can pull 50-60Mbps off hours.
In my experience, these kinds of connections are QoS'd on a per-port/protocol level, so every client gets an equal amount of bandwidth on that port. If you can get a tunnel or vpn connection going on a less used port you'll generally get far more bandwidth. Being on a non-standard port also helps since the systems are often under provisioned for the size of the NAT table they have to hold.
That's all assuming you can get an open port between a remote server and you, but usually there's at least some way to get a connection on not 80/443.
That said my experience is pretty out of date so it could be different these days. Thinking back, since I figured out that I could tether my motorola v710 for free 10 or so years go, mobile internet has gotten faster and far more reliable, (though a lot more expensive once smart phones made data plans more than an underutilized $5/mo gimmick on feature phones,) I've rarely used public wifi.
Getting good Internet when you visit a town every few days and working offline while at sea is fine once you get used to it.
Maybe that's just because it's how I grew up with networks, doing everything in batch mode. ("Bluewave offline email", for example https://en.wikipedia.org/wiki/Blue_Wave )