Short answer
For coastal North Carolina, a professionally installed full-flake polyaspartic system over a diamond-ground, moisture-tested slab is the most reliable choice. It resists UV yellowing, cures well in humidity, and handles salt exposure far better than DIY epoxy kits.
Why the coast is hard on floors
Three things make coatings fail near the water: ultraviolet sun, salt, and moisture. Sun ambers and breaks down coatings that aren't UV-stable. Salt is corrosive and abrasive, and it gets tracked into garages constantly. And humidity both slows the cure of cheap coatings and can drive vapor up through the slab, pushing a coating off from below.
A coating that ignores any one of these will look bad or fail early in Wilmington. The right system accounts for all three.
Why polyaspartic wins here
Polyaspartic topcoats are UV-stable, so they hold their color even where sun reaches the floor through an open door. They cure quickly and reliably in humidity, which shortens downtime and reduces cure-related problems. And they stay flexible, so they tolerate the temperature swings a coastal garage sees.
Paired with a proper moisture test and, where needed, a moisture-mitigation primer, a polyaspartic system stands up to the coastal environment in a way that a big-box epoxy kit simply can't.
Preparation matters more than the product
Even the best coating fails over a badly prepared slab. Mechanical diamond grinding (not acid etching) and moisture testing are what let the coating bond permanently. This is the step budget installers skip, and it's the number-one reason coatings peel on the coast.