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Costal ecosystems like coral barrier reefs and mangrove forests have been designated as environments in need of protection. This is not only because they are threatened by climate change, but also because of the important role they play in coastal protection. Some field studies based on Rhizophora mangrove trees have analyzed the force induced by water flow over their roots and the wave dissipation capacity of these trees under tidal regimes and sea waves. Various methods have been used to calculate energy dissipation in the past, but these do not include the drag coefficient (C-D) with field data calibration. The study presented here was conducted to investigate the capacity of a small natural Rhizophora mangrove patch (at experimental scale) located on Isla Grande in the Colombian Caribbean Sea to mitigate wave energy. The total energy dissipation, including the slope bottom and the effects of vegetation, was calculated. Parametric equations were used to calculate the effects of vegetation. The drag force (F-D) was computed using Morrison's equation and the C-D was calculated using Mazda's method. The results show a mean energy dissipation difference of 9.6% between the energy balance and dissipation coefficients wherethe C-D was calculated for each sea state. The dissipation coefficients were calculated with constant C-D values (0.06, 3.48 and 6.90). None of the three cases could explain the 90.4% energy flux, as in the case of vegetation dissipation (D-veg) with calculated and non-constant C-D values. Despite the small size of the mangrove patch, the results show an increase in the C-D (with values of up to 7.9) as a result of lower values of the Reynolds number (R-e) (about 7.3 x 10(5)). This demonstrates experimentally the role that even a small patch of mangrove vegetation plays in attenuating sea waves (as C-D is a function of sea states), and higher magnitudes were obtained than those recorded in the literature using other vegetation types. A nonlinear contribution to energy flow by bottom dissipation and vegetation dissipation was observed. Our results highlight the need to scale measurements up to forest level in order to accurately quantify the impact of mangrove vegetation on wave attenuation and determine the possible impact on the protection of coastal ecosystems and infrastructure. (C) 2017 Elsevier B.V. All rights reserved.