A rigorous assessment of marine atmospheric corrosion at a controlled NRL test site in Key West Florida was conducted. Certain factors which have been previously implicated in the literature as controlling, or at least heavily influencing, the corrosion of engineering materials in atmospheric exposure were isolated and explored. In this study, low carbon steel witness coupons were exposed to assess atmospheric corrosion. In particular, the effect of steel alloy type, coupon width, location, and exposure condition were tested. Coupons were exposed under ambient condition, sprayed with sea water, or rinsed with clear water. Results were assessed in terms of steel mass loss. Several important findings relevant to experimental design of atmospheric corrosion were assessed. Coupons treated with sea water experienced substantially greater corrosion rates compared to coupons exposed ambiently. Samples rinsed with clear water experienced lesser corrosion rates compared to ambiently exposed samples. Furthermore, corrosion rate differed by location: coupons exposed closer to the salty ocean water experienced greater corrosion compared to ones exposed further inland. Coupons with a thinner width also had greater area-normalized corrosion compared to wider coupons. The results of this study will benefit the entire atmospheric corrosion community since it establishes what the best practices are for exposure.