What impact did u-boats have on the WW2?

Question:just need to know.. also..
"When were U-boats made??"
"How was it used?" --> i know for shooting down cargo ships supplying britain, but anything else?
thanks everyone for your help.

Best Answer - Chosen by Asker: just need to know.. also..
"When were U-boats made??"
"How was it used?" --> i know for shooting down cargo ships supplying britain, but anything else?
thanks everyone for your help.

Background:

The first submarine used in warfare was the "Turtle", It failed to sink a British warship in New Yotk Harbor during the American Revolution.

The first submarine to sink an enemy warship was the CSS Hunley, sinking the USS Housitonic outside Charleston Harbor in 1864.

Work on submarines continued, with the Spanish developing the first practical submarine capable of firing torpedoes while submerged in 1888.

All this to let you know that the Germans did not invent some singularly diabolical device for conducting marine warfare.

The German Unterseeboot (U-boat) gained prominence in WW I, first striking the British naval cruisers at Scapa Flow. With the German High Seas Fleet bottled up, the submarine became their commerce raider, a role originally envisioned for cruisers. Range limits restricted most of their activity to the waters around the British Isles, including the sinking of the Lusitania on May 7, 1915. Because the ship was a passenger liner, even though it carried cargo, and because it was sunk without the U-20 surfacing and giving warning, the death of almost 1200 people was considered proof of the degeneration of "The Hun" from standards of civilized warfare.

The Central Powers considered submarine warfare as being a counter to the blockade they endured, with growing shortages of food and material as production fell under the weight of the massive conscriptions. Napoleon had tried to blockade Britain but Nelson's victory at Trafalger and the failure of Russia to abide by the Continental System had thwarted that effort. Submarine warfare therefore was not the first attempt to strategically use commerce interruption as a strategic weapon against Great Britain.

WWII

After Versailles, German development of submarines continued in Holland. Once Hitler declared Germany would rearm, that included rebuilding Germany's Navy. U-boats were more quickly built and were on hand when Germany invaded Poland, at least two years before the German Naval staff would have on hand enough capital ships to challenge the British Navy. German commerce raiders were quickly put down, with the sinking of the Bismark effectively ending German surface interference with Allied shipping.

U-boats in WWII has sufficient range to patrol off the American Atlantic coast, the Gulf Coast, the Caribbean, and the slot between Africa and Brazil. Organized in "wolf packs" they were sinking British shipping faster than it could be replaced. The Biritsh maritime crisis impelled FDR to move America from its strongly held "never again" isolationism (Little Orphan Annie's foster father was "Warbucks" for originally being a "war profiteer") to "all aid short of war." That provided Britain with WWI era 4 stack destroyers to up its anti-submarine forces while the US got bases on British possessions. More importantly, the US navy began escorting convoys as far as Iceland and were in engaged in combat with German submarines before Pearl Harbor. The USN Reuben James was the first ocean war ship sunk in WWII.

With Hitler's declaration of war after Pearl Harbor, all restrictions were off attacking American maritime commerce. So many tankers were sunk off the Gulf and Atlantic coasts that gas rationing was instituted to keep vehicles deemed essential to the war effort running. It's not there was not enough gasoline produced, but it could not be reliably delivered in quantity to the Northeast ports cities until the Big Inch Pipeline was completed.

With submarines based in French ports on the Bay of Bisacy, they were so effective that 1942 was touch and go as to whether Great Britain, and the growing military forces collecting there, could continue to be supplied. Improvements in anti-submarine measures, better sonar, "hedgehog" depth charges, more naval escorts types (destroyer escorts and corvettes, "Jeep" carriers - "escort" carriers - CVE's), and above cracjing the German naval code enabled the odds to be turned against the attackers. Over the course of the war, there was no more hazardous German military service.

In addition to more effective ASW measures, the American shipyard reinivented the process of building cargo ships to a standard plan. Liberty Ships and Victory ships slid down the ways, many built by "Rosie the Riveter," at their peak being completed in 60 days after laying the keel as opposed to six months to a year. Increased production meant that as U-baots were having to maneuver slowly under their snorkel breathing tubes, more tonnage was making the passage from the US and Canada to Britain and North Africa or Italy.

Although their most renowned service was as commerce raiders, German submarines also took a toll of Allied warships, including the British aircraft carrier, Ark Royal. Submarines, even more than Italian aircraft, meant resupply through the Mediterranean was not possible until enough airbases were secured to make Axis submarine operations there a death wish. Submarines also served as supply boats, not only for hunter subs, but for German ground forces in the Black Sea and North Africa. By the end of the war, there were subs large enough and with long enough range to ferry messengers and supplies, including aircraft prototypes, to the Japanese.

Aftermath:

The German U-boat forces did not win the war for Germany, but "it was a damn near run thing." The success of German submarines carried over to Soviet naval efforts, which focused on submarine fleets to interdict Allied ocean borne supply and reinforcement. In return, American and British naval efforts focused on anti-submarine warfare (ASW) efforts, including the development of "hunter-killer" submarines whose function was to kill other submarines.

Try the following links for more information:

they did a lot of damage to US ships giving Britain/USSR goods (before US joined the war) although uboat warfare didn't pull US into the war (like WWI) it definitely generated anti-German seniments, because a lot of navy soldiers drowned when Germany torpedoed the US ships. Uboats are basically submarines that have torpedoes and missiles to shoot ships (destroyers) > although the US had sonar & other technology to find uboats, a lot of US ships were destroyed by uboat warfare.

Germans started to use subs since WWI,
their sub sank the Lusitania, a reason why US got into WWI

then, German's industrial production does not allow them to build big air craft carriers, (although they tried to, but them it's obvious that they cannot compete with Britain and US)

so they used the u-boats to sink convoy ships, aka "unrestricted submarine warfare", to attack British morale