However, don't be discouraged! It is still possible to anchor out in wonderful places all over the world, and even within or near many of the most popular harbors in the world. Even in Florida. Despite the apparent magnetic attraction of other boats, all it takes is a little imagination and research to find thousands of anchorages that nobody is using, or almost nobody.
A few summers ago my wife and I discovered a new and wonderful anchorage in Narragansett Bay, close to Newport, with a beautiful beach, perfect protection for the weather, and we were the only boat there after dark.
How did we do it? There are a few techniques we use. First, we carry onboard just about every chart and cruising guide there is for the area we are in. I don't use one guide over the other--I tend to buy them all, and I keep old guides forever. For example, one of my favorites is Julius Wilensky's cruising guide to Cape Cod (covering the islands too) published in 1976. He reproduces in black & white detailed charts that are long out of print, yet they are much better than anything currently available from the government. Sure, the information on marinas and services is totally out of date, but I'm not interested in that stuff. Instead he talks about all sorts of interesting little anchorages in places like the Elizabeth Islands where you can still be the only boat after nightfall even in July.
Second, we scour the charts for places that few, if any, writers have ever mentioned. There is no reason you can't anchor someplace new, is there? You will notice lots of coves and shallow areas that aren't mentioned in guides, yet some of them can be perfect if the weather cooperates. That's a big caveat in a lot of these unknown anchorages, but in the right season with the right forecast it can be very nice in New England to anchor in some bight where the wind whips across some spit of sand and behind you is nothing but open bay or ocean for miles. We have found places like this in the Caribbean, in Florida, and all up and down the East Coast. Monitor your weather and anchor someplace that maybe wouldn't be a good storm hole, but if there is no bad weather coming, who cares?
Third, you have to develop a mindset of thinking for yourself when cruising. There are some interesting interactive online cruising guides out there, and some of them are touting following the actual routes of folks who uploaded their's. Frankly, that would bore me--who wants to just follow in somebody else's wake? Blaze your own course to someplace new!