SW,
Marco Island and the Naples area in general, is our favorite place to visit when in Florida. Nice, relatively uncrowded, clean beaches, many small intersting small museums and attractions in the Naples area, swamp buggy rides into the Everglades are nearby (you'll need a car, of course, to get to all these places) most of the larger hotels on Marco Island have kids programs, if you're bringing your kids along. If you're a fisherman, you'll be in your realm, as the snook, tarpon, and redfishing is not far, and you can rent a boat and motor near-by, or hire a guide. Freshwater fishing is also super in the 'Glades for bass. In all cases, both fresh and salt water, you'll need a fishing license. And Naples has its pier out into the Gulf of Mexico, for fishing or just watching. Magnificent sunsets on the Gulf side, and you should be past the hurricane season, so you should be okay.
Restaurants and shops in nearby Naples tend to be a bit pricey, but most are worth it.
Bring lots of suntan oil, and have a blast.
Swamp buggy races in a nearby park, but I don't know how often they run them.
bj-21.
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'Tis better to have played and won, then never to have played at all.