It is possible that the advice in this book seem mundane when we benefited from the advice of a coach. But when was formed - somehow - crawl alone in this guide seems to me much more interesting, especially useful, as everything I had read previously on this subject. Its two essential qualities in my opinion are one hand allow to really understand the technique of the crawl: why is this the most effective swimming, how can the body adapt better to the movement in aquatic environments, and above all, what are the blunders and mistakes that we lose energy, which can not "slip" in / on the water, which ultimately hinders its own movement. In addition, this guide provides remarkably focus on the sensations he must learn to (re) locate to feel good in his movements: sensation of floating comfortably on one side of the body and then the other, the importance of the rolling sensation, sensation of hanging water for propulsion, sensation of being well balanced on the water, to not have to struggle to keep afloat and eventually sinking, although sensation spread on the water with a "game" of the shoulders that give a "fairing" slender body, all aimed at giving the overall feel to effectively swim without effort - and breathing efficiently and pleasantly. All presented clearly and legibly. In my opinion, remarkable book.