I've given this some thought, as I live in Florida. I plan to spend the rest of my life here. My house was built in 2001, and like most Florida homes, it is built like a bunker.
My home is about a 45 minute drive from the beach. I've checked the flood charts and impact of rising oceans in my area and I am fine as far as the worst case scenarios estimate. But a lot more will happen here that I will no doubt be impacted by. Global Warming isn't just about the oceans rising, which they are, and you can read up on how its already affecting Miami (pumping stations), but it will also cause more hurricanes and make them more destructive. Areas along the coast will flood, and even regions like the Everglades may be severely impacted by the rising saltwater (and since water flows from north to south, once that water rises, the water flowing from the north will have nowhere to go. The damage from all of this will impact tourism, insurance, land values, and so on. I am not sure I will see the day where parts of a city are permanently underwater with structures sticking out of the surf, but I do see areas of coastline that people will abandon or no longer develop on. Then again, there are a lot of idiots out there. Also, sea walls will be useless as most of Florida sits on limestone which erodes pretty badly (sink holes), and the ocean water will just seep through it.
This apocalyptic view is some ways off, but it is coming. But by the time it happens, Louisiana, Galveston, New York, etc etc will all have their own problems too, so it will be a nationwide disaster. Hopefully I will be dead by then.