Funny you mentioned sea, I just watched The New Swiss Family Robinson, 1998 James Keach, Jane Seymour movie this afternoon. A movie about a family's sailing boat crashing and them getting stranded on an island. ,
Yes, it is much more time docked in the marina than cruising the seas, but still an interesting lifestyle choice. I know one person doing it in the Chicago area from April through October, then spends the rest of the year living in his condo. If I were single I think I'd give that a shot, but the wife isn't going for that at all. I loved boating during my younger years, but it's an expensive toy. B.O.A.T. equals bust out another thousand. Between maintenance, slip fees, and fuel you best have about 10 grand a season to burn through. That's why you see so many people who have boats that rarely leave the marina.
You can go from New Jersey to Miami without ever really leaving the intracoastal, although since I sail I purposely go outside to get some wind and open water. If you have a low enough air draft you can actually go through the Okeechobee Waterway and stay intracoastal all the way to Texas, otherwise there's an open area from Miami around to central west coast FL. It's actually possible to do the Great Circle route through the St. Lawrence seaway, Great Lakes, and down the Mississippi then the intracoastal which could easily be an enjoyable two years of retirement, wintering over somewhere south, without ever being out of sight of land!
There is a good article in Latitude 38's March issue a US couple completing both the US & the European loops ( Great Circle).