Taking to the ocean in a houseboat may sound unusual and a little threatening, but a trip out to the Sanibel and Captiva Islands isn't quite like motoring to the Bahamas. These lovely white-sand barrier islands are close to Florida's shores.
These islands are all palm and Australian pine. A large portion of Sanibel Island is preserved as a national wildlife refuge, notable for its many species of birds, which you can easily spot from the deck of your boat. Not that Sanibel and Captiva Islands are purely wildlife - there's more than enough civilization on the islands to keep you supplied when you moor.
If you're after a quicker houseboat experience, many marinas open out into the Caloosahatchee River, a broad, gentle river that flows into the gulf. You'll likely travel this river if you visit the islands, but if you want a shorter trip, you might want to try wandering north to Fort Myers, or just a little south to the Florida beaches.