This is a floating watertight structure which can be submerged sufficiently to receive a ship by flooding the pontoon tanks which form the bottom of the dock.
Esi sisakhiwo esingangenimanzi, esinganty wiliselwa ngokwanelelye ukuze samkele inqanawa nyekuzalisa itanka lesikhitshane eliyingxenye nemzantsi wedokisi.