Surfaces that would decrease marine biofouling attract considerable theoretical and practical interest in the last decade. Recently, it was demonstrated that engineered topographically corrugated surfaces are capable of reducing biofouling because the fouling organisms that are larger than the primary length scale of the surface texture would exhibit reduced adhesion strength as there would be fewer attachment points. However, when roughness and chemical heterogeneity is introduced to a surface, then usually a large contact angle hysteresis, (H = θ adv - θ rec) is found showing the deviation from the ideal flat and homogeneous surfaces. There are reports that H of the substrate has some effect on biofouling and coatings having the lowest H show the best biorelease properties. In all of these publications, H and the critical surface tension (γc) values of substrates were measured under air. Relating these values to the underwater biofouling process is an indirect method and unjustified because low-energy surfaces in air tend to form high-energy interface in aqueous solutions, and vice versa. Thus, there is a need to determine (Hunderwater) values for better correlation to bioadhesion. Underwater contact angle measurement can be done by applying the two-liquids contact angle method and its combination with the one-liquid method have been discussed. In this work, we show the determination of underwater contact angle hysteresis of rough, hydrophobic polymer surfaces using two-liquids and air bubble in water methods and discuss its possible implications on biofouling.