During the past few years there have been considerable changes in the approach to ship stability, so far as it affects the merchant seaman. The most obvious of these is the introduction of metric units, in addition, examination requirements have been increased and recommendations for a standard method of presenting and using stability information have been produced, which will undoubtedly be reflected in the various examinations. This seventh edition has been designed to meet all these requirements. Basic information contained in early chapters has been retained for the benefit of anyone who is not familiar with the subject. The remainder of the text has been re-arranged and expanded, as desirable, to lead into new material which has been introduced, there is also a chapter on stability information to illustrate the standard method of presentation. The theory of stability has been covered up to the standard required for a Master's Certificate and includes all that is needed by students for Ordinary National Diplomas and similar courses. This has been carefully linked up with practice, since the connection between the two is a common stumbling block. Particular attention has also been paid to matters which may be misunderstood, or not fully appreciated by seamen.