The Naval Research Laboratory has developed an airborne gravimetry system for marine use. The system utilizes global positioning system navigation and high-resolution radar altimetry to overcome the major difficulties of Eotvos correction and vertical acceleration determination. Precise measurements of aircraft motions permit system operation in the noisy low-altitude environment and allow averaging data over fairly short periods. This results in good system response to short-wavelength gravity anomalies. Preliminary analysis indicates average errors of 4 mGals or less on three aircraft profiles over a gravity equipment evaluation range for a flight altitude of 150 m and air speed of 400 km/hr.