This is a generic reference book which covers most of the major warship classes from the ironclad era to WW2. A few post-war missile cruisers are also mentioned, but it largely focuses on gun-armed ships. Most of the entries are 1-2 pages, and provide a brief history and discussion of the design or advances of the particular class. There's a few photographs or paintings of each ship, a good number of which are color. Each class has a brief stat box including build date, dimensions, machinery/speed, armament, and crew complement. The cruiser sections also state endurance and protection. Battlecruisers are included, and are lumped in with the battleships.
The book doesn't seem to follow any logical order, so it's hard to find a particular ship without the index. It's subdivided into sections for pre-dreadnoughts, WW1, and WW2 for battleships, and pre-WW1/post WW1 for cruisers. There is some general history and topics of interest describing both ship types. The pages are pretty thick, and the book itself is hardbound and of good quality.
Other reviewers have noted a British slant from the authors, and it's certainly true- in fact I'd go so far as to say they're downright biased. I couldn't help but notice that the authors repeatedly downplay the weaknesses of RN ships such as the lack of flash-tightness in the WW1 battlecruiser designs and have sections dedicated to things like the sinking of the General Belgrano in the Falklands War (1982, way beyond the scope of anything else in this book) while barely mentioning key events like the sinking of Force Z off Malaya. Probably because that casts the RN in a slightly less favorable light, hm? I also liked how the very first entry, about the groundbreaking French ironclad Gloire, is half taken up by assertions that HMS Warrior was better in every way. Yeah, I know she was, but couldn't that have waited until Warrior's entry on the next page?! Come on, guys...
There are some errors and otherwise incorrect information, especially regarding the non-British ships. For example, in the Colorado-class entry the author says that both Maryland and West Virginia were sunk at Pearl Harbor and raised. That's incorrect, only West Virginia was sunk. The Deutschland-class are listed among the battleships, but they aren't battleships by even a loose definition of the term. Additionally, most of the specs given are as-built, not how they ended service. This is fine for the most part, but makes the work a bit incomplete since some ships are mentioned again as modernized, and others (which were also comprehensively updated) are not. There is also often no stats given for armor protection or endurance in the battleships/battlecruisers section, which is a bit odd.
Generally speaking, I'd say this is still a good book for those interested in the subject and it has a lot of nice pictures. It's also a whole lot cheaper than some other similar books, so makes a good 'poor man's guide' to classic big-gun warships.
Lots of pictures
Not super expensive, good quality binding
Good general information about most of the important ships and classes spanning from ironclads to WW2 (a big period!)
Written by Brits, clearly for Brits.
No line-drawings. Would have been nice.
No protection/endurance stats for battleships.