Sorry for the late reply, but I recently read Pacific Crucible by Ian Toll about WWII at sea in the Pacific. It is an excellent narrative telling of the entry of the United States into World War II with plenty of background information about naval sea power and the wide reach of Alfred Thayer Mahan's book, The Influence of Sea Power Upon History. He explains that naval battle strategies that had not changed significantly for hundreds of years were forced to be reconsidered after the rise of the airplane. From there, we arrive at the Japanese attack on Pearl Harbor, which Toll paints in vivid detail. Like the subtitle says, Toll very closely follows the "War at Sea in the Pacific, 1941-1942" without a single misstep. I thoroughly enjoyed it.

It usually doesn't give me any trouble. I have run into issues where I was reading non-fiction about the Napoleonic Wars and also a historical fiction book about naval warfare during the Napoleonic Wars. As one might guess, I had trouble remembering what actually happened and what was fiction. As long as I avoid situations like that I'm usually okay, hah.

I try to read a healthy mix of both. At any given time, I am usually reading at least one non-fiction and one fiction book simultaneously. These days I have been reading a lot of history and fantasy/science fiction.