A fantastic book. A touch on physics but kept to be understandable by your average person, lay man terms. Any diver will be able to relate well to the essence of the book. This was possibly one of the first books, or at least the first I read, about the huge amounts of Carbon that are continually being recycled naturally as they have done for millions of years, through the Ocean floor. Through the devastating sea bed mining and trawling we are not only destroying reefs and feeding grounds for fish that have taken centuries to evolve but also releasing huge amounts of sequestered CARBON back into the atmosphere. Potentially more than we are ever capable of on the land.