The reserve buoyancy of a submarine when on the surface, measured by the capacity of the main ballast tanks, is much smaller in proportion to the surface displacement than in surface ships .
Amandla okudada agciniweyo enkwili xa ingaphezulu, alinganiselwa ngamatanki angundoqo anzima alayishiweyo ukuzinziya inqanawa, mancinci kakhulu xa ethelekiswa nawenqanawa eqhelekileyo ehamba phezu kwamanzi.