Can the cruise companies be sued for enforced compliance?
Can they be sued if I acquire the virus while on your ship?
You need to look up contract of carriage. It’s a voluntary contract that you and the transport services provider are entering into. They have every legal right to put any conditions they wish into that contract as you have every legal right to refuse to enter into that contract being a mutually voluntary contract. Every conservative should be behind the absolute sovereignty of contract law with a private business. Don’t like the terms don’t use their services it’s that simple. Getting the government to force terms on a business you don’t like when you have no capital interest in that company neither stock nor bond holdings is fascism by definition and every conservative should oppose that. If a company chooses to put unpopular terms in their contracts of carriage then the market will decide how inpactful that is to their profitability not the government.