Hopefully we'll be out there with Carey come Saturday.
Fossile Bay is a pretty average anchorage for here, Eric. But like the other bays on Sucia, Fossile has a lot of park buoys in it. Boats have decent anchoring room in the outer half of the bay but the inner half to 2/3 is pretty much taken up by two rows of park buoys.
As you probably know there is a nightly fee for using a marine park buoy or dock. So far as I know there is still no fee for anchoring out in the marine parks. However, anchoring is "discouraged" in water less than 30 feet deep around here because of the potential damage to the eelgrass beds. I seem to recall there is even a "no anchoring" zone just outside Cap Sante marina in Anacortes for this reason although I may be misremembering that.
All the park buoy anchors used to be big concrete blocks but they have all been replaced by screw anchors that hold the buoy mooring line off the bottom. Same reason--- protect the eelgrass beds.