A method is described for measuring the wall shear stress on the hull of a ship model using a three-hole Preston tube. Integrating along the direction of the wall shear stress, the limiting stream lines are obtained. The velocity distributions in the boundary layer are also measured using the three-hole Pitot tube. Some of the cross flow profiles measured at the after stations are of the type of the so-called reverse cross flow. Further, the author proposes a new prediction method for the development of the three-dimensional turbulent boundary layer on a ship hull on the basis of assumption of the reverse cross flow profile and the employment of the crosswise moment of momentum integral as an additional auxiliary equation. The results of the calculation agree fairly well with the measured.