In order to understand the state of the oceans, researchers turn to the origins of global waters, 90 million years ago. This study explores the subject of sea-level change in the Phanerozoic era, a topic which has much relevance to current issues of climatic shifts and the greenhouse effect.
An excellent reference, perhaps just a little bit out of date. A new edition incorporating the last 30 years of research is probably needed; as is, one needs supplemental material from work published since then to get a better picture.