The invention relates to underwater drilling for procuring and analyzing ground samples of a bed of a body of water. An underwater drilling device placed onto a bed of the body of water. By a drill drive a drill rod composed of at least one tubular drill rod element is drilled into the bed of the body of water in a first drilling step, wherein a drill core is received in a receiving part in the tubular drill rod element. The receiving part with the drill core is deposited in a storage place of a storage area on the base frame. Subsequently, one further drilling step is carried out with a further drill rod element. By means of sensor means at least one physical and/or chemical property of the drill core is determined. data on the storage place of the drill core in the second storage area.