At least with Android, simply logging into the ship's wifi with the phone and then connecting the Firestick ( or google tv) to the phone's shared wifi works like a charm for me.
I think it's less a matter of the ship doing something on purpose than it is one of the annoyance of some devices having trouble connecting to "captive" wifi systems--i find the similar system is required when using some communal wifi systems in large universities for example.
anyway, hope that helps and have a great trip!