Read: Shock Wave
I think I have not noticed this before but with Shock Wave it became rather clear. One of Cussler's strengths is setting up the historical backdrop of his novels. Once in a while, I would really like to read only these parts if they came as a full fledged novel on their own.
Or do I become a little tired of Dirk Pitt? Always the hero, indestructible and with his luck never running out. Maybe Cussler felt the same. Two years after Shock Wave he published the first NUMA Files novel that features a different protagonist while still taking place in the same timeline and universe he created with Pitt. Actually, these novels got me started with reading Cussler.
That being said, Shock Wave was fast paced and exhilarating as ever. A new evil (economic) super power is introduced, almost Bond-like I dare say. I wonder whether they will re-appear in the next novels as a more active ingredient to mix of adventure, science, global politics, and secret agents.