Obviously, if you liveaboard and are in your homeport, you should expect to be treated like a local and receive the same rights along with the same responsibilities. Sadly, this is not often the case in my experience. Liveaboards are considered close to homeless people by some, and if your boat has a hailing port from somewhere else you will be considered to be from there no matter how long you have been tied up in one place. I have purchased boats with various hailing ports, and without fail we are assumed to be from the location featured on the stern.
This can really hit home when you try to move about and your out-of-state driver's license doesn't cut it with the local police. Is your health insurance local to the state you are in? Where is your doctor located? Do you own a car with out-of-state plates? All of a sudden you find your clever parsing of state laws in order to avoid paying some tax or another might not have been the best idea. In short, if you plan on living aboard in one locality for long, make it your real home (your domicile) for tax purposes, and follow all the local regulations for drivers' licenses, car registration, etc.
Then there are the cruisers who are truly transient, moving from place to place, with no real fixed "homeport." Don't be surprised if you find yourself at the nasty end of pointed questions with regard to your hailing port or the flag you are flying. In times of crisis people become very tribal and rightly or wrongly defend their home turf. Most of us would do the same. Think of how you would feel if the positions were reversed--you're looking out from your waterside home and see a boat arriving with a hailing port known to be a hotbed of the virus. Your boat and you may not have been in your hailing port for months or years, but that is where you are assumed to be from. Ask anyone driving around the country with New York license plates what type of reception they are getting right now.
Port in a Storm
So where can a cruiser go when the world is shut down? One huge advantage we have is the ability to carry lots of longterm stores, water, and fuel. Cruising boats are perfect for self-isolation in many ways. The virus doesn't travel far, and if you are anchored out or on a mooring you are unlikely to have much contact with anyone carrying the virus.
In some ways, being on a long passage might be the ideal spot to be, personally, but eventually you have to find a port that will allow you in, and some may not. Avoid heading offshore for that reason. You won't know where you will be able to end your voyage safely, and you don't want to find yourself ordered to quarantine in some horrible commercial port.
Many of us have certain ports we have visited over and over again because we love them, and possibly have friends who live there. Those friends ashore could be your key to finding a safe port in a storm. With the local tribe hunkering down and trying to prevent an influx of outsiders you need that inside help. The close friend ashore might make a huge difference if you need assistance such as needing a car to get groceries or medicine. Also, those local friends will know others that you might need help from: the local mechanic, the police, the health clinic, the harbormaster.
However, often you will be far away from that favorite port with the friends ashore, so what should you look for in a safe harbor? The #1 feature, I believe, is to head to a port that is boat friendly. You want to be in a place used to seeing lots of cruisers coming and going from all around the country and the world. That type of harbor also has lots of local boaters who may themselves have been cruisers at one time or another. Those people ashore will know what you on your boat need, and chances are very good the local officials will know and understand what you are doing.
Ports in the USA that fit this description include Newport, Rhode Island, Annapolis, Maryland, and Fort Lauderdale, Florida. These places already have hundreds or thousands of boats tied up with hailing ports from everywhere, and chances are great that you and your boat will be able to instantly "fit in." In a place with lots of fellow boaters you will quickly become part of the local tribe. The customs officials will understand, the harbormaster will understand, the police will understand, and many local people will understand. You want to be in a place with robust services of all sorts, including transportation. You want a port where you could leave your boat indefinitely if you had to.
Choose a port that is on the mainland so there are good connections via road, train and air. Good transportation connections mean your purchases at the local supermarket won't be a burden on the system. Needed supplies should still be plentiful. You'll be able to purchase fuel for the boat, get water easily, find repair parts.
I have been lucky enough to live in some of these places, and I have visited them by boat many times. Yes, they are busy, and services are not always the cheapest, but there has always been an understanding that cruisers are welcome. Cruisers are part of the lifeblood of these major ports, and therefore you are appreciated for what you bring to the local economy.
Plus, they tend to be fairly large communities, with much more robust healthcare systems. That lovely, isolated island in Maine or the Bahamas may be a great place to get away from it all, but it probably has very limited medical capacity during normal times, if any. During a pandemic people from away will not be welcome when a single additional person burdening the healthcare system could mean life and death for someone who lives there year-round.
It may seem counterintuitive to some, but now is not the time to head to an off-the-beaten-path place. Those are the very places that are terrified of outsiders right now, and rightfully so, because each additional newcomer has the potential to bring the virus with them or to become a burden on local limited resources.
This is a time to stick together and be in a place where all around you are other boaters just like you. You won't stick out, you will fit in.