Correct, in that no guide = no boat. No boat = more limited options, but options exist if someone was adventurous:
The Flats/areas in front of Sueno Del Mar, Blue Reef and between Sundiver/Journey's End all can be waded. Head north in the AM and walk/wade/fish south and you'll have the prevailing wind at your back as well as the sun. Lot's of bonefish, permit on the fringes of the flats, small permit in the turtle grass. I've caught both (bonefish and small permit) within 50 feet of our front door.
Again, guide = obviously more local knowledge, but if someone wants a DIY experience (which can kind of be inferred from the title of this thread) there is such experiences to be had on AC. Remember to get your sport fishing license.
If you're here for 2 weeks, personally I'd do both (guided and unguided.) The former letting you experience some of the truly great fishing areas the island has to offer, the latter offering you quality time wading, casting and enjoying the surroundings/serenity.
Many men go fishing all of their lives without knowing that it is not fish they are after. ~Henry David Thoreau