Mae'r cwcis hyn yn gwbl angenrheidiol ar gyfer weithrediad y wefan.
Rydym yn defnyddio Google Analytics i fesur sut ydych yn defnyddio'r wefan er mwyn i ni ei wella yn seiliedig ar angen defnyddwyr.
Gall y cwcis hyn gael eu gosod gan wefannau trydydd parti a gwneud pethau fel mesur sut rydych yn gwylio fideos YouTube.
Amgueddfa Cymru
Hydrological launch SONIARUS at the entrance to Queen Alexandra Dock, Cardiff, during a visit by Gibson Watt MP, who is seen with hydrographer L.H. Williams at the observation hatch in the roof of the launch.
British Transport Docks Board's hydrological survey launch SONIARUS (54gt) was built at Brightlingsea by James and Stone Ltd. It was powered by twin English Electric diesel engines and launched on 15 October 1969.
