Below is a nice discussion, copied from the Net's "Ask Your Nieghbor" page (/ask_your_neighbor/ask_your_neighbor/), about an anchorage, hard by old Fort Mantanzas, south of St. Augustine, and near where the AICW splits off from Mantanzas River. Take care – bottom strata can shift here quickly due to the swiftly moving waters.

Does anyone have local knowledge of the depts for the  anchorage at Fort Matanzas [south] of St. Augustine at mile 792.  We draw 5  feet.  Will we have a problem entering this anchorage?  Can you visit the fort from here?
Jeff and Susie Parker
M/V Idyll Time

Jeff
Fort Matanza is south of St Augustine. We stayed there last spring and had no problem our draft is 4. 6" The current is strong but not a problem.  You have to dingy over to the beach near the ranger dock and take the free ferry over to the fort they would not let us tie up the the dock. The fort was a very nice stop we stayed two days take a dingy ride out to the inlet if you have time.
Larry & Margie Ross
Wanderin L&M

We went in  there last year.  We followed instructions in Skipper Bob.  There is a fair amount of current coming and going through the pass to the ocean.  Dingy into the visitors center, they will take you to the fort.  A great stop, and adds to the understanding of the early history of St. Augustine.
Chuck Gorgen
ODYSSEE

We have been in there and anchored with 4'8" draft and never had any trouble. be sure to set your anchor well as the current is very strong through there.. I have visited the fort waling the dog but never officially visited it. the tour boat that takes people there is on the opposite shore just east of the fort..
Jay and Susan Wigginton
M/V SAILS

Ft. Matanzas is south of St. Augustine, not north. It is a nice day anchorage but I wouldn't trust it at night since the currents can be swift. We are having a raft-up there tomorrow with 4 trawlers and 2 smaller boats. We draw 4'11". We'll get there about an hour after low tide and leave before the tide changes.
Barry Kipnis