The specifics of your TV and each network need to be looked at separately. Without know your device or how each network is configured, it's tough to give a definitive answer. Here's a document that has more than you probably want to know. http://www.cisco.com/c/en/us/td/docs/routers/access/wireless/software/guide/SecurityAuthenticationTypes.html

When you get the message: "vizio tv connected but download not available" Probably your TV is failing to load the web browser in response to a script telling it to launch the browser (so you can log in and authenticate your device's MAC address).

Bottom line -- You can't fix your TV, so you can try a work-around (no guaranty it will succeed): Buy a wireless access point (WAP) such as an Apple Airport Express and use it as a gateway to connect your on-board devices to the Internet WAP at the marina. Log in using a computer or tablet that uses the on-board private WAP as a gateway, so the private gateway MAC address gets recognized and authenticated. Then you can connect with everything onboard using a single login.

Edit: changed Apple Airport Extreme to Apple Airport Express