The estimated wind speeds included in COADS are based on the old WMO Code 1100 Beaufort equivalent scale. As already discussed in section 4.4, there are serious biases associated with this scale and several alternative scientific Beaufort equivalent scales exist (WMO 1970, Cardone 1969, Kaufeld 1981, Ramage 1987). The purpose of this section is to document the performance of these Beaufort equivalent scales using individual ship reports in COADS. Having diagnosed climatological biases in these scales, we introduce in section 5.3 a very simple formula (eq. 6) to correct estimated wind speeds reported in COADS. The performance of this correction for individual oceans, seasons, and decades is briefly discussed in section 5.4. The impact of our estimated wind speed correction on the long term climatology and wind speed trends is discussed in section 5.5.