This study presents momentum flux measurements in moderate to strong winds using two methods: Reynolds flux and dissipation. Measurements were conducted on a deep water tower operated by the Bedford Institute of Oceanography, and on a ship (CCGS Quadra). The Reynolds flux method involves measuring the covariance of vertical and horizontal velocity components, while the dissipation method estimates fluxes from turbulent kinetic energy dissipation. Both methods showed good agreement for wind speeds between 4 and 20 m/s. The dissipation method, which does not require direct measurement of vertical velocity, was found to be more suitable for high wind speeds and moving platforms. The drag coefficient (CDN) was found to be independent of stability and fetch for fetch/height ≥ 800, but increased with wind speed above 10 m/s. A formula for CDN was derived based on wind speed at 10 m height: CDN = 1.2 for 4 ≤ U10 < 11 m/s and CDN = 0.49 + 0.065U10 for 11 ≤ U10 ≤ 25 m/s. The study also showed that CDN is smaller during rising winds than during falling winds or after a change in wind direction. The results from this study and other deep water measurements suggest that the drag coefficient is relatively constant in the open ocean for wind speeds below 10 m/s. The study also compared the bulk aerodynamic method with direct measurements, finding that the bulk method can be used to estimate momentum flux when stability is unknown. The study found that the bulk method can provide accurate estimates of momentum flux in the open ocean, especially for wind speeds below 10 m/s. The results also showed that the drag coefficient is sensitive to wind speed and stability, with higher values observed in unstable conditions. The study concluded that the dissipation method is a viable means of measuring momentum flux in the open ocean, at least up to wind speeds of 20 m/s. The results also showed that the drag coefficient is relatively constant in the open ocean for wind speeds below 10 m/s, and that the bulk method can be used to estimate momentum flux when stability is unknown. The study also found that the drag coefficient is sensitive to wind speed and stability, with higher values observed in unstable conditions. The study concluded that the dissipation method is a viable means of measuring momentum flux in the open ocean, at least up to wind speeds of 20 m/s.This study presents momentum flux measurements in moderate to strong winds using two methods: Reynolds flux and dissipation. Measurements were conducted on a deep water tower operated by the Bedford Institute of Oceanography, and on a ship (CCGS Quadra). The Reynolds flux method involves measuring the covariance of vertical and horizontal velocity components, while the dissipation method estimates fluxes from turbulent kinetic energy dissipation. Both methods showed good agreement for wind speeds between 4 and 20 m/s. The dissipation method, which does not require direct measurement of vertical velocity, was found to be more suitable for high wind speeds and moving platforms. The drag coefficient (CDN) was found to be independent of stability and fetch for fetch/height ≥ 800, but increased with wind speed above 10 m/s. A formula for CDN was derived based on wind speed at 10 m height: CDN = 1.2 for 4 ≤ U10 < 11 m/s and CDN = 0.49 + 0.065U10 for 11 ≤ U10 ≤ 25 m/s. The study also showed that CDN is smaller during rising winds than during falling winds or after a change in wind direction. The results from this study and other deep water measurements suggest that the drag coefficient is relatively constant in the open ocean for wind speeds below 10 m/s. The study also compared the bulk aerodynamic method with direct measurements, finding that the bulk method can be used to estimate momentum flux when stability is unknown. The study found that the bulk method can provide accurate estimates of momentum flux in the open ocean, especially for wind speeds below 10 m/s. The results also showed that the drag coefficient is sensitive to wind speed and stability, with higher values observed in unstable conditions. The study concluded that the dissipation method is a viable means of measuring momentum flux in the open ocean, at least up to wind speeds of 20 m/s. The results also showed that the drag coefficient is relatively constant in the open ocean for wind speeds below 10 m/s, and that the bulk method can be used to estimate momentum flux when stability is unknown. The study also found that the drag coefficient is sensitive to wind speed and stability, with higher values observed in unstable conditions. The study concluded that the dissipation method is a viable means of measuring momentum flux in the open ocean, at least up to wind speeds of 20 m/s.