It is now nine years since the first edition appeared and much has
changed in marine science during that time. For example, satellites are
now routinely used in remote sensing of the ocean surface and
hydrothermal vents at sea floor spreading centres have been extensively
researched. The second edition has been considerably expanded and
reorganised, and many new figures and tables have been included. Every
chapter has been carefully updated and many have been rewritten. A new
chapter on man's use of the oceans has been included to cover satellites
and position fixing, renewable energy sources in the sea, seabed
minerals, oil and gas, pollution and maritime law. In this edition we
have also referred to a number of original references and review
articles so that readers can find their way into the literature more
easily. As in the first edition, PSM has been mainly responsible for the
text and lIC for the illustrations, although each has responded to
advice from the other and also from many colleagues. In this context
readers should note that the illustrations form an integral and major
part of the book. The text will almost certainly be too concise for many
readers if they do not study the illustrations carefully at the same
time. The book has been written as an introductory text for students,
although it can serve anyone who is beginning a study of the sea.