I only read one book, so I can't say I know a lot about the rest of his writing. Clive Cussler's writing style seemed amateurish for the amount of books he's got in print.
Most of them aren't even written by him. I've had one customer say that one of this other authors (I forget which one) was the only ones they'd read. i've never read any myself, but as I work in a bookstore and seem to forever be overstocked in whatever his latest novel is, I have an unreasonable dislike of him. Dean Koontz has really slipped, but at least he still writes his own books. Piers Anthony has also really slipped, I put it down to old age. His latest Xanth novels are painful.
Tom Clancy Red October was average. Red Storm Rising was dull. Nothing but expensive sounding weapons specifications blowing up other expensive sounding weapons specifications. After that his books became increasingly bloated wish fulfilment fantasies. Clear and present author avatar Jack “Gary Stu” Ryan keeps getting promoted to increasingly higher positions in the US government and eventually becomes president. In between espousing Clancy’s political views he goes on to defeat just about every threat to the US, real and imagined, in increasingly anticlimactic military smackdowns.