Prior to the description of how the battle itself unfolded, the author gives a comprehensive review of who the principal characters were and how their personalities and actions influenced Spain's decision to proceed with the launching of the Armada (which they called "The Enterprise of England"). These include not only the sovereigns of Spain and England at the time, but also the Pope, lesser (but nevertheless influential) religious figures, politicians, ambassadors and, of course, the main combatants, including Sir Francis Drake and the Duke of Parma (both of them spoiling for a fight). In fact, the progression of the battle as it wound its way along the southern coast of England is almost anticlimactic (not the least reason for which is because we know the outcome anyway). Nevertheless, we are made aware of several key engagements (or near-engagements) during the course of the battle when things could have gone horribly wrong for the outnumbered English fleet and affected the final outcome.
If I could level any criticism at the book, it could have done with more and better maps to guide the reader through the battle and the lead-up to it. There are only a couple, and even then, there are places mentioned in the text that don't appear on the maps provided. There are also a few puzzling printing errors near the edges of some of the text, but it's obvious to the reader what words were intended. Fortunately, the occurrence of these errors is only in a few places.
That being said, it's still a rollicking good read that I couldn't put down until I'd finished it in a couple of sessions. When I did finish it, I loaned it to a friend who finished it in a single reading because he couldn't put it down and gave it back to me the next day!