Have you ever been driving along a section of Gulf Islands National Seashore and noticed a lettered PVC pipe like this sticking out of the sand, seemingly in the middle of nowhere? These posts are important to volunteers like me who patrol the beach in the summer, looking for sea turtle nests.
If you can, imagine riding along the shoreline in a mule looking for turtle tracks when you come upon a nest. The next thing to do is call a bio-tech to come out and ascertain whether the nest can remain where it is or if it must be relocated, then staked and documented properly. What do you say when the bio-tech asks your location? "Uhhhhhhh...I'm on the beach." That's a big stretch of seashore for them to scour. A much more appropriate answer would be something like, "I'm at Santa Rosa, approximately 25 yards east of Marker G."
Markers such as these begin one-half mile into the Gulf Islands National Seashore on either side of Pensacola Beach, both Ft. Pickens area and Santa Rosa area, and continue every half mile along the beach. On the Ft. Pickens side it starts with marker A, one-half mile past the entrance and ends up with marker N near the old fort. On the Santa Rosa side it begins with marker A one-half mile past the entry sign and ends with marker N near Navarre Beach.
Now you know the reason for the markers!