The theory and relevant illustrations along with specific commentary make this a unique and mandatory Must Read for anyone considering serious sailing conditions in a junk rig sailboat. If you are going to design your own rig, you've still hit the jackpot. This book will save you about a hundred years of costly mistakes, serious wallet aches, and may even save your life. The Junk rig is fantastic , but like any rig you need knowledge to use it correctly and safely. By the way, I'll take the Junk Rig over anything out there today, it is forgiving, inexpensive, more durable than dirt, and usable in heavy weather as well as sunset cruises on a smooth day. With so little pressure on any point of the sail, they just don't rip. You could shoot holes in it with a shotgun and you wouldn't affect performance much. Try that with a western rig, and the pressure would rip it apart. I can't give this book anything but 5 stars.