The order of Dirk Pitt novels follows their release sequence. Starting from the first one which introduced the character Dirk Pitt and his exciting adventures. Each subsequent novel builds on the character's development and the overall story arc. Some of the well - known early novels set the foundation for the series and as the series progresses, the stories become more complex and the scope of Pitt's adventures expands.
The Dirk Pitt novels are typically numbered in the order of their publication. For example, 'Pacific Vortex!' was one of the early ones. However, you can also group them thematically in some cases, like those that focus more on underwater adventures together and those dealing with land - based mysteries in another group.