Tide charts near Fort Johnson
- South Chan. 0.4 mi. NW of Ft. Johnson
- South Chan. 0.8 mi. ENE of Ft. Johnson
- South Channel Buoy 32
- Fort Sumter
- Folly I. Channel N of Ft. Johnson
- Castle Pinckney 0.4 mile south of
- Castle Pinckney 0.6 mile southwest of
- Charleston Harbor (off Fort Sumter)
- Rebellion Reach 0.8 n.mi. N. of Ft. Sumter
- Charleston Harbor Entrance