Government should not be able to mandate gun-free zones for the vast majority of public spaces and public services.
If private business wants to do so, they can do it like how it is done in FL.
Signs don't carry the weight of law. They have to tell you in person. Disney does that. You walk through a metal detector, and they tell you to secure your piece in your vehicle if you had one on you.
Since places like Walmart and Dolphin Mall are too lazy/cheap to go Disney's route, you can carry even if they post signage that says no. Since signs don't carry the weight of law and they didn't tell you in person.
So, if American Airlines wants to ban guns, they're private property, they can set up their own security and such. They can also be liable for any injuries or loss of life due to their anti-gun policies if terrorists or other dirt-bags cause harm/death on a flight.
If Amtrak wants to ban guns. Nope! Government owned and operated. Government can't violate civil rights.
Same goes for buses, ferries, etc. If they are government owned, you should not be barred from carrying. Publicly owned bus? Can't be a gun-free zone. NYC ferry service? Can't be a gun-free zone.
Disney's ferry service between their parks and hotels? Hey, they're private and they can assume all the reasonability and liability for being anti-gun.