The book is a fast-paced mystery and detective story about a diving adventure to recover the treasure from a large Spanish galleon captured by the British warship HMS Monmouth in 1702. It had sunk after hitting a submerged rock during the battle off Vigo Bay, Spain. The book also vividly describes the dangers that the crew of the dive boat encountered. Interspersed are lively vignettes about celebrities that the author meets.This final book by John Potter details the pioneering thought patterns of the man who encountered onerous problems of open-ocean, deep-water salvage and solved them. It is a true-life work seasoned with the delicious spices of the glitterati, world events, and--occasionally--personal peccadilloes. His vignettes are lively and fun. Potter meets celebrities including Errol Flynn, Richard Burton and Andres Segovia. A significant event involved the sinking of the Ave del Mar off of Vigo in 1956. Twenty–five fishermen were lost. Potter and his crew spend three weeks searching the stormy ocean bottom for this wreck. Eventually they are able to recover twenty–three of the bodies. This was extremely important to the victims' families because they believe without a Christian burial it would be impossible for the souls of their loved one to travel to heaven.Stylistically, On the Track is impressive. The author's descriptions are vivid and his knowledge of European history encyclopedic. In all, it is a spellbinding story of shipwreck research, tenacity and the exciting search for one of Spaiobn's richest sunken treasures. Readers feel like they are part of the dive team. And, there is a fascinating ending to this story!