The threshold velocity of surface currents causing the entrainment failure for oil booms is investigated and an empirical formula for the threshold velocity is proposed. A theoretical prediction of the deformation of the skirt of an oil boom due to surface currents is made, and the results of the prediction are verified by laboratory experiments. The skirt deformation results in reduction of the effective boom draft which in turn degrades the effectiveness of the boom. The motion of oil booms excited by the ocean waves are predicted and verified by experiments. The degradation in the boom effectiveness due to the wave motion is discussed. The effectiveness of tandem booms in trapping the leaked oil is investigated and a method of predicting an optimum separation distance between the two booms is described.