The naval battle at Trafalgar was an important victory for the British Navy over the combined fleet of French and Spanish ships. With perhaps a bit of hyperbole, the author notes that (Page 5): ". . .on 21 October 1805 off the south-west coast of Spain, 60 such vessels [ships of the line:] representing Britain, France, and Spain fought the greatest naval engagement in history."
The book provides ample detail on the structure of the opposing fleets (names of ships and number of guns (pages 9, 12, and 13), a schematic of HMS Victory (the flagship of the English fleet) and detail (but no drawing) of the French ship Redoutable (both on page 10), brief sketches of leaders of their respective fleets (e.g., Admirals Magon, Collingwood, Villeneuve, Gravina, and, of course, Nelson),specifications of ships of the line (the rating system, sails, masts, armament, etc.).
There is discussion of the respective fleets. The battle, though, is the centerpiece here. An illustration on page 41 outlines Nelson's rather interesting approach to battle. Ships of the line were so named because these large vessels would line up and fire broadsides from the "lines" thus formed. Nelson deployed his ships in two lines and attacked the French and Spanish fleet in perpendicular fashion rather than in line against the combined opposing fleet.
There is considerable detail on how navies fought at the time. There is a statistical analysis, indicating the bloodiness of the battle. Finally, the aftermath and ultimate impact of this battle on the course of the Napoleonic wars.
This is a slender volume, but serves as a nice introduction to the subject for an amateur like me.