The SEASAT altimeter has been calibrated for height bias using four overflight passes of Bermuda that were supported by the Bermuda laser. The altimeter data was corrected for tides, by using recorded tide gage data; for propagation effects, by using meteorological data taken around the time of each pass; for acceleration lag; and for sea state bias, including both surface effects and instrumental effects. Altimeter data for each of the four passes was smoothed and extrapolated across the island. Interpolation between passes then produced an equivalent altimeter measurement to the geoid at the laser site, so that the altimeter bias could be estimated without the use of a geoid model. The estimated height bias was 0.0¿0.07 m.