def absolute_vertical_stability(F_z, W_sub, gamma_SC) ->'abs_vert_stab_uty':
    """Absolute vertical stability unity check. 
    Reference:
    DNVGL-RP-F109 (2017-05) 
        sec:3.6.1, eq:3.39, page:31 
    """
    abs_vert_stab_uty = gamma_SC * F_z / W_sub
    return abs_vert_stab_uty
