1. Why the Germans were defeated in this battle?
The main reason that the Germans were defeated is that Kriegsmarine was not as powerful as the opponent and had poorer supplying capability, that is to say the Germans lost in a war of attrition. Although German submarines achieved outstanding results and threatened substantially the transportation line of the Allies, it was undeniable that the main targets of German submarines were civil vessels. Submarines could not defeat a lot of escort warships of the Allies, especially after anti-submarine technology was improved in the late period of the war. To conclude, the results of the Germans were based on the condition that there was not enough escort warships of the Allies. Before the U.S. joined the war, Germany still had the chance to defeat Britain in a war of attrition. But after the United Stated was involved, this possibility no longer existed. German submarines could not confront directly with naval force of the Allies, so once the number of escort warships of the Allies was increased, it was necessary that submarine warfare suffered from defeat.
2. What was the consequent if Germany won this battle?
At first, if Germany wanted to win, it must be before the U.S. joined the war or Germany did not launch the war against the Soviet Union. If before the United Stated was involved in the war, Germany won in the Battle of Atlantic, Britain would get itself out of the war and like France reached some agreement on peace with Germany. In that way, no one could ever change German position in Europe. If Germany did not start the war against the Soviet Union and continued to obtain a lot of raw material supplies from the latter, then even if the United States joined the war, this sea battle would become a war of attrition lasting for a very long time provided that the two sides had equal strength. And the final result could be that the two sides achieved comprise because either one could not defeat the other.
3. How did the sea control of the Atlantic change during the whole war?
Firstly, the sea had always been controlled by the Allies during the whole war and only vessels of the Allies could transport material supplies through the Atlantic while Germany could not. Germany sending a lot of submarines to escort its merchant ships was completely realistic. The Allies could easily destroy such escort ships because German submarines could not fight against the warships of the Allies. Therefore, the best Kriegsmarine could achieve was that either side could not complete material transport. Kriegsmarine originally intended to develop surface and underwater forces at the same time, but the plan was not accomplished because the war broke out earlier. Thus, when the war just broke out, Raeder, Commander in Chief of Kriegsmarine anticipated that Kriegsmarine would be defeated due to the disadvantage of the naval size.
4. To maintain the necessary operation, Britain needed to import at least more than 1 million tons of raw materials and other goods per week. So sea transport was extremely important to Britain.
5. The Battle of Atlantic lasted from the beginning to the end of the World War II. It was the longest battle in the war.
6. The result of this battle had little impact on Germany. For Britain, however, once it was defeated in the battle, it could not continue to fight.
7. Although it was a sea battle, the two sides suffered from huge casualties. There were more than 70000 people died in the Allies, a half of which were common people. Among those common people, most of them were sailors on merchant ships. There were more than 30000 people died in the Germans.
8. 3500 merchant ships of the Allies were sunk with a total tonnage of 14.5 million.
9. The escort fleet of the Allies lost 175 battleships while the Germans lost 783 submarines.
10. Kriegsmarine sunk civil vessels no matter from warring or neutral countries, causing deaths of a lot of common people. At the beginning of the war, a plenty of cargo ships from Sweden, Norway, Denmark etc. were sunk by German submarines.