Length: 400 pages including appendices and index. Grooss is a Danish naval historian, and tries in this book to be comprehensive in telling us what happened in the Baltic Sea during the war years. He gives us a little history, going back to the Viking times, of the various wars that have taken place in this sea, leading into WWII. From there he tells us about the various battles, from the invasion of Poland, and the efforts of Polish ships to escape to Britain, or the Baltic states, or Sweden. He describes the Orzel incident, with their escape from Estonia, and run to Scotland. He goes into the Winter War, the invasions of Denmark and Norway, then the U-boats training in the Baltic. From there, it's Barbarossa and how the navies of Germany and the Soviets were unprepared. He also goes into the tightrope walk Sweden took in making sure they could support Germany with iron ore, and transit of German troops by train, and later in the war, making sure Allied and Polish servicemen got home. We finish out with the German Operation Rescue, with Admiral Doenitz trying to get wounded men and refugees out of East Prussia and Courland, and the losses of the Wilhelm Gustloff and other ships to Soviet mines, aircraft and subs. He brings in the other theaters of war a bit much for my liking, and since he's trying to help the neophyte, he ends up bringing many sidebars which I didn't think were needed, like figuring naval gunfire or talking about Type XXI U-boats. It's an ambitious book, and overall does all right, but depending on what you may already know, you may end up skipping over some things like I did.