The Rogue Submarine series began with the publication of Rogue Avenger in 2005. As of Rogue Justice, launched Aug 30, 2017, there are ten books in the series. John Monteith intends to continue the series indefinitely.
For ease of tracking, each novel has been published in alphabetical sequence (Rogue A, Rogue B, Rogue C…). Each novel is a self-contained story, and the order of reading is a matter of personal preference. However, a recommended order is to begin with the latest book to determine if you like the direction of the series, and then go back to Rogue Avenger. Another recommendation is to simply begin with Rogue Avenger and move through sequentially.