As a boater and someone who hates the cold I am considering relocating to Florida when I FIRE.
Where do you think the best place to live in Florida and why?
If you hate the cold, stay in the lower ½ to ⅓ of the state. The northern portion of the state can get chilly in the winter..
You say boating, but that covers a lot.
My DF lives in Lake County northwest of Orlando. There are a zillion lakes, many are connected by canals and excellent for "lake style" boating. Many houses are built on canals and have boat docks or lifts. The cost of living is very reasonable in this area as well. It's not really rural, but most of the people there are "country" as my DF describes it.
My DM lives in Fort Lauderdale. They also have extensive canals filled with boats. Many might be called yachts. Nice access to the Atlantic Ocean. It's also much more reliably warm there in the winter. Cost of living can be high (if you live in a nice area). If you like city life, south Florida is the place for you.
There are tons of other variations on the Florida theme all around the state. Different mixes of water access, cost of living, temperature. You really need to visit various parts of the state to get a feel for it.
One last word. Summers are REALLY hot there. The humidity is something you have to experience to understand. When my DM wanted to move there permanently, she rented for a year to prove to herself that she could deal with the summers. She did and loves it there now. But doing something like that may save you from the cost of a big move there, and a big move back later.