A good sailor knows his knots but still, it's not a bad idea to have a reference work available on the boat. Many knot books have thousands of examples, as if the purpose is to demonstrate the number of knots that the author knows. This book is not one of them. It contains instructions on just 7 bends, 8 hitches, 7 loops, and a few in other categories. That means that the reader's favorite knot may not be in the book, but due to the author's careful selection, a knot can probably be found for any need one might have.
The limited selection means that the book itself is small and light, with legible print and drawings - just what a sailor might need in a sticky situation. This is not a book for idling away the hours musing over the ingenuities of the sailors of old. It is a reference work for getting the job done, or a primer for the beginning sailor working on his repertoire.
While all the examples are not sailing knots per se, most of them would be useful at sea. The Prusik Knot of course is a climbing classic, but also serves to scale a halyard to reach the masthead. The Fireman's Chair Knot is another one that is not a sailor's creation but a worthy adoption.
The Running Bowline is a useful knot for retrieving something dropped overboard since it can be looped over something and then will tighten under pressure. For the bowline collector, it is another one to add to the Portuguese, Eskimo, Double, Water, Brummychan and Chinese varieties that he undoubtedly already knows.
This little book can be bought for little more than the cost of shipping from Amazon.com, and is well worth tucking away in a small corner of the boat.