On Royal Caribbean, it's much simpler. You can open a hotspot and allow other devices to connect. We paid for one device, and friends and family could connect whenever they were nearby. At one point, we had up to 8 connected devices with no issues.
Why the Google hate in this case? I'm in love with my chromecast I've had for the past 6 years with no issues, and this seems like a great upgrade for less than I paid.
I visited last November from the San Jose side, and the road was a nightmare. It's a small, windy road through the mountains with little visibility. I could see it being extremely difficult to navigate with firetrucks as it took me quite a while with my Prius.