This book cannot be read by itself...it is the companion of the first volume 'Land' and canbe fully understood only if the bondage techniques of the first book have been practised well.
This book doesn't describe the simple construction ties in which Shibari is based but goes directly to the suspension practices. Suspension is a complicated subject in bondage and most people prefer to do it using special equipment. In Shibari you can do such thing by just using ropes, it is a form of art (in suspension even more than in the ground) and this is the magic behind it.
Again in this book Safety advices are given, in greater degree than the first volume (logically) and also more explanations about potential hardware which can be used.
Again the book explains some basic suspension techniques and gives ideas for further explorations which is the perfect approach to Shibari in my point of view.
In any case this book is one of the kind because although you can find many books for Shibari bondage on the ground, I doubt if it is something else out there for suspension techniques