Yes, this really doesn't even cover half of the story. Also, Culebra has a similar story, though the Navy left in 1975.
Culebra is a "Must-See" for all of those who travel to Puerto Rico. It is a tiny little island off the East coast of PR. You can catch the ferry at Fajardo. The ride is about two hours or so, and well worth it! Definitely head to Playa Flamingo, which is one of the most beautiful beaches in the world.
Culebra is uncommercialized, there is no McDonald's or Burger King. If you want to get away from it all, Culebra is the perfect place for you. Guaranteed...
I made a minor change to the section about needing to rent a car. If you're staying in San Juan, you don't have to get a car. My wife and I took the public buses (0.25 or 0.50) between our hotel and Old San Juan. A discussion of the bus system should probably go in the San Juan article, though, I suppose.