Geological research ship. Artwork of a geological research drilling ship. Ships like this are used to study the structure & composition of deep seabed rocks, and find bacteria living within them. Seabed rocks contain sediment layers which are not eroded or disturbed like those on land. Ships like this can drill in water which is over 8000 metres deep. Such ships are kept in position by thrusters during drilling because the water is too deep for anchors. A re-entry cone (white) is placed on the seabed at each drilling site to allow it to be found again during a later mission. Samples ('cores') taken by the drilling bit can be analysed in the ship's laboratories.