Tyndall AFB, FL Coastal Erosion Rate
What USGS measures 6 miles southeast of Tyndall AFB, FL
Good news, and an honest one: USGS's data can't distinguish this stretch, 6 miles southeast of Tyndall AFB, FL, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
The grain of this number
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Tyndall AFB, FL, rather than showing one arbitrary line. Segment center: 30.02, -85.53. USGS's Gulf of Mexico assessment last surveyed this stretch through 2001, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
Where this fits nationally
11 transects feed this segment's number; 100% of them individually measured retreat. USGS's confidence interval here is ±4 ft/yr. The unadjusted figure here, -1.55 ft/yr, would place it 154 of 1211 if ranked directly - but an unreliable rank isn't a useful one, which is exactly why "no significant trend" is the headline instead. Source: USGS Open-File Report 2004-1089. Rank 1045 nationally for growth belongs to Gardiner, OR, 2310 miles from this stretch, measured at 0.59 ft/yr. Tyndall AFB, FL, 1.4 miles off, is the adjacent measured stretch, itself no significant trend.
Tyndall AFB, FL on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.