DEEP OCEAN CORING - RECENT OPERATIONAL EXPERIENCES OF THE DEEP SEA DRILLING PROJECT.

During recent years, many changes and innovations in deep sea drilling techniques and equipment have been required to meet the objectives of an increasingly sophisticated and diversified scientific program. These include such developments as a deep-penetrating hydraulic piston corer, drill string design improvements and a bit releasing mechanism. Methods of deploying instrumentation for specialized geophysical investigations were devised. An additional challenge lay in maintaining the efficiency of the drilling vessel in the face of a research schedule with an increasing amount of on-site time and rising operating costs.