You'll need to find 6 waypoints to get the final location. They aren't all signs, some are fixtures. A few people have got stuck and my recommendation is to look high and low for the answers. Here are the clues:
Waypoint 1 N37 42.987 W122 30.212
Battery Davis' guns blasted BG00 pound shells through it's barrels.
Waypoint 2 N37 43.177 W122 30.228
The date above the Battery Davis name is 19D8.
Waypoint 3 N37 43.212 W122 30.270
Clues available in the hint. On the Corps of Engineers U.S. Army Survey Point the year of the station designation is F5.
Waypoint 4 N37 43.297 W122 30.246
Construction began on Battery Davis in 193H.
C=H-1
Waypoint 5 N37 43.505 W122 30.232
E = The number of times the letter 'B' appears on the sign.
Waypoint 6 N37 43.347 W122 30.172
A = The number of screws holding the horse and rider sign. As the sands of time have swept the sign away, the answer is the number of legs a horse has.
Final cache is located at N37 AB.ACE W122 DE.EFG
There is room for small items but not for a pen so please bring your own.
You can validate your puzzle solution with certitude.