The paper outlines the present state of the art of deep sea drilling and discusses some of the problems with the 'controlled' as well as the 'uncontrolled' techniques. The first method is being developed by the contract drilling companies under the auspices of the oil industry, while the second method was introduced by the Deep Sea Drilling Project under the guidance of a group of oceanic institutions (Joides). The oil industry has drilled controlled in water depths of up to 1000 m and slightly over, and is now capable of extending the technique to 2000 m. Joides contemplates controlled drilling in water depths to 3650 m, say by the end of 1981. It is suggested that not only the slope but also the rise of the continental margin should soon be investigated in a number of suitable localities in order to assess adequately the potential of the last remaining major unexplored frontier for oil and gas. The paper emphasizes that it is already possible today to carry out controlled exploration even to water depths of over 4000 m. If such exploration were successful, production could also be achieved by making use of the presently developing under-water technology in 200-300 m of water.