What began as a farfetched idea 50 years ago, drilling a hole into the sea floor from a floating vessel, was successful and soon opened up an exciting new era of ocean exploration which continues today. The Ocean Drilling Program, by obtaining long cores of sediment and ancient rock from the floors of the world's oceans, has been making discoveries that have challenged old ideas and brought entirely new concepts to light. Drill ships have evolved and become more sophisticated, enabling scientists to drill in greater water depths and progressively deeper into the sea floor.