I doubt very seriously that you will find a good anchorage, let alone a marina, that is not pretty well populated that weekend. Look for us on Daydream, we will be out July 1st through 3rd (have company coming for the 4th, drats, old friends from NJ we haven't seen in 30 years, oh, well...) I almost hate to share this place it is so neat, but check out Reef Cove, between Tumbo and Cabbage Islands (read the entry for either Tumbo or Cabbage in Waggoner). There are about a dozen buoys there, but you could also drop the hook, there is quite a bit of room. A dinghy is pretty much a necessity, no docks, and Cabbage Island especially is worth a walk around.