There is much uncertainty concerning the atmospheric boundary layer over the Gulf of Mexico. There are now available new boundary layer observations from six oil platforms, including 915-MHz radar wind profilers, 2-KHz Radio Acoustic Sounding Systems (RASS), and near-surface routine meteorology instruments. Two of these meteorological stations are operating from May 1998 through September 2001 and four are operating from October 2000 through September 2001. The profilers measure winds and RASS measures virtual temperatures between the surface and heights of a few kilometers. The surface stations measure sea surface temperature as well as wind speed, wind direction, air temperature, and mixing ratio at an elevation of about 25 m. These new data, in addition to the traditional data collected by buoys, are being analyzed to investigate the overwater surface energy balance and boundary layer structure for both steady-state horizontally homogeneous conditions and for conditions variable in time and space. These three-dimensional, time-dependent fields will be used for analysis of transport and dispersion from overwater sources. A three-year climatology of fundamental boundary layer scaling parameters such as the surface roughness length, zo, the friction velocity, u*, the scaling temperature, T*, the scaling water vapor mixing ratio, q*, and the Monin-Obukhov length, L, in addition to latent and sensible heat flux, are being estimated using the so-called TOGA-COARE algorithm. From these parameters, the mixing depth, h, and the vertical profiles of wind speed, temperature, and water vapor mixing ratio are also being estimated. The outputs of the COARE program (e.g., the boundary layer scaling parameters and the energy fluxes) and the estimated profiles are being compared to data collected by the radar profilers and RASS, and Eta model data.