Clive Cussler writes reliably entertaining and clean stories. No, they are not great literature just purely escapist fun. With Spartan Gold, he and co-writer Grant Blackwood have written the first in a series featuring husband and wife adventurers Sam and Remi Fargo.
While in a Maryland swamp looking for a different treasure, Sam and Remi happen upon a World War II German submarine. In it they find an old wine bottle, part of Napolean's Lost Cellar. They discover that the label contains clues to an even greater treasure and set out to find the other clues and eventually the treasure. Unfortunately, they are not the only ones looking for it and their competitor isn't willing to play by the rules.
Spartan Gold has just a few swear words, nothing major, and no sex. The only problem I had with the book (other than the plot holes but it is escapism after all) was the violence. Sam and Remi had no problem getting themselves into trouble and then fighting to get out of it. To me, it seemed that they really shouldn't have been some of those places and so the killing wasn't really justified. Rated PG-13 for the violence.