As noted, WiFi calling but test it thoroughly. In itself, for me WiFi calling has been very spotty in terms of reliability and most cruise lines will charge an arm and a leg for WiFi access. Chances are if you're using Visible, you're cheap like me anyway.
Best advice as former cruiser myself... turn the phone off and leave it off or just use it for photos. Enjoy the cruise!
Check your cruise line emergency calling procedures (ship-to-shore) and leave the info with whoever is not going at home. Usually ship-to-shore calling runs around $7.95 per minute - that helps to ensure it's a real emergency whether an inbound or outbound call 😀