def peak_horizontal_load(r_toty, rho_w, D, C_y, U, V) ->'F_y':
    """Peak horizontal load for on-bottom stability check. 
    Reference:
    DNVGL-RP-F109 (2017-05) 
        sec:3.6.4, eq:3.40, page:32 
    """
    F_y = r_toty * 0.5 * rho_w * D * C_y * (U + V) ** 2
    return F_y
