The reviewer appreciates the internal consistency of the Dirk Pitt series, noting how past events are carried forward. However, they found this book to be more focused on action and political espionage rather than salvage, which is their favorite aspect.
The reviewer notes that each Dirk Pitt novel by Clive Cussler builds a more intense and divergent world from reality. They appreciate the internal consistency of the series, where past events like the merger of Canada into the United States are carried forward. The primary plot of Deep Six revolves around kidnapping and mind-controlling the President, which the reviewer finds entertaining but not as engaging as the salvage aspects they enjoy. The book also offers an interesting perspective on political changes, given the time that has passed since its publication. Overall, it's a fun read but not the best in the series.
Quick quotes
With each Dirk Pitt novels, the world Clive Cussler is building seems to get more and more intense and diverge further from the world we live in.
One thing I do appreciate though is how internally consistent these books have been so far.
I think my biggest negative with this book is that it was really about salvage, which is my favorite part of the books.