It can't. If the ship has an HTML network authentication, the watch can never get on. It's MAC address would never be authenticated, so there would never be a timeout, because it would never be on.While that's all true, how would the watch be able to function independently of the phone if it's unable to login to the cruise ship's html authentication page? Even if it was somehow able to function for a time after you logged in with your phone, which I doubt, the connection would time out and you wouldn't be able to login again.
The point of this post was to equate a likely ship network to a hotel network. They are likely to be the same. The AW would not work in a hotel, and it would not work on a ship.