I am surprised that this is not on here since of its age, but here you go, the real reason the Bismarck sunk, according to this article.


Visiting Bismarck, Explorers Revise Its Story
By William J Broad
THE Bismarck was the world's most feared warship, a Nazi superweapon meant to sever the convoy lifeline that kept Britain alive in World War II. Its guns could fire one-ton shells 24 miles. So upon its debut in 1941, the British responded with everything they had. Resolve grew steely after the Bismarck destroyed the Hood, considered Britain's finest ship, killing all but 3 of its 1,415 men. "Sink the Bismarck!" became the battle cry.
After being pursued by a fleet of British ships and aircraft, and constant pounding by shells and torpedoes, the Bismarck went down in 3 miles of water, 600 miles off the coast of France, on May 27, 1941. It was the eighth day of the warship's first mission. The victory became a monument of British pride and, in time, a hit film, a popular song and a small industry of Bismarck books and television shows.
There is just one problem. New evidence, detailed in interviews, videotapes and photographs, suggests that the story is wrong.
"We conclusively proved there was no way the British sank that ship," said Dr. Alfred S. McLaren, a naval expert who studied the wreck on two expeditions, this year and last. "It was scuttled."
This conclusion is still hotly contested by British researchers. But five expeditions have reconnoitered the site, and three independent teams of American explorers, including Dr. McLaren, a retired submariner and emeritus president of the Explorers Club in New York, have concluded that the famous ship is in surprisingly good shape.

No major damage from enemy fire is visible on the sides of its hull, the American explorers say. That fact alone, they add, suggests that the Bismarck was in fact scuttled - as German survivors have claimed all along, saying that their naval tradition was to deliberately sink ships in danger of falling into enemy hands.

David Irving comments:
NOW what did I write in Hitler's War (published in 1977) and then in "Churchill's War", vol. i: "Struggle for Power" (published in 1987). Oh yes:
Churchill's War: ... The biggest battleship in the world was no longer a fighting machine, but she was unsinkable. Her guns fell silent by ten a.m., their last ammunition spent. A message from Admiral Tovey arrived in London: the battleship could not be sunk by gunfire. It did not matter, because even as Churchill's Cabinet met at ten-thirty to accept the loss of Crete, engineer officers aboard Bismarck were blowing open her seacocks to scuttle her. She went down at eleven a.m.
Hitler's War: ... At noon Hitler learned that the British government had announced the sinking of Bismarck an hour before. Disabled and her last ammnition spent, Bismarck had scuttled herself under the guns of the British navy; she sank with her colours honourably flying and the loss of some twenty-one hundred lives.HOW was I so sure of this? I had been told the facts by Rear Admiral Puttkamer, Hitler's naval adjutant (back to camera in the picture), who passed the reports on to the Führer. Now that is how Real History is written.
I wonder what we would have found in a history of the episode by Prof. Richard "Skunky"Evans? Probably wild fantasies about SS officers on board shooting fleeing sailors, and plotting further atrocities, as they screamed "Heil Hitler!
The American conclusions have infuriated the British, who denounce them as revisionist claptrap.
"I just don't buy it," said David L. Mearns, who last year led a British expedition to the wreck. "Bismarck was destroyed by British gunnery and sunk by torpedoes." Anything else, he added, is ridiculous.
The newest assault is by James Cameron, director of the 1997 movie "Titanic." His television documentary - to be shown Sunday on the Discovery Channel - is based on an expedition last spring in which Mr. Cameron explored the Bismarck with robots and piloted submersibles. The expedition was able to probe the wreckage more deeply than earlier investigations.
Would the wounded Bismarck have sunk without the scuttling? "Sure," Mr. Cameron said in an interview. "But it might have taken half a day."
The new observations are challenging ideas about the Bismarck's end that once seemed self-evident, at least initially. In 1941, the British got a lucky break when an aircraft fired a torpedo that crippled the battleship's rudders. British ships then moved in, relentlessly firing rounds of shells and torpedoes.
Waves of German sailors abandoned the Bismarck as it sank, the men bobbing in the oily waters. The British picked up some survivors, but soon fled the area upon reports of U-boat activity. Of nearly 2,200 men on board the Bismarck, just 115 survived.
The German sailors told of setting off scuttling charges - explosives most military ships carry that shatter water intakes and other weak areas near the ship's keel. They said that those charges - exploded about 30 minutes before the sinking, and before the last torpedoes hit - were the real cause of the Bismarck's demise.
A British Admiralty report during the war concluded that German explosives might have hastened the ship's end, even if they were not the exclusive cause. But British patriots dismissed that idea.
New light on the controversy came when Dr. Robert D. Ballard, a discoverer of the wreck of the Titanic, subsequently found the Bismarck's resting place in 1989. The sinking battleship, he discovered, had slid down an undersea mountain for nearly a mile.
Despite the war damage and rough landing, it was in remarkably good condition - even a faded Nazi swastika was clearly visible. As for the ship's conning tower, he wrote in "The Discovery of the Bismarck," published in 1990, "Its heavy armor still looked capable of warding off enemy fire."
Dr. Ballard used a tethered robot that could not see far sideways, limiting his views of the hull's sides. He nevertheless leaned toward the scuttling theory, saying he saw no signs of large air pockets, which would have been crushed by rising water pressure as the ship sank.

Such implosions shattered Titanic's stern. By contrast, the sunken Bismarck was largely intact. So it had apparently been completely flooded, suggesting, Dr. Ballard wrote, "how effective the scuttling was."

More than a decade later, in June 2001, people dived to the wreck for the first time, using two Russian minisubs, and the American explorers were able to study the Bismarck's sides closely. The trek was organized by Deep Ocean Expeditions, a private company. Experts, including Dr. McLaren, peered from portholes as video cameras operated by the Woods Hole Oceanographic Institute on Cape Cod photographed the ship.
The explorers could examine the hull only where it rose above the muck at the bottom. But the visible areas revealed no significant damage from enemy fire.
"You see a large number of shell holes in the superstructure and deck, but not that many along the side, and none below the waterline," recalled William N. Lange, a Woods Hole expert on the voyage.
More important, no major breach was found in the 13-inch-thick armor belt that girded Bismarck above and below the waterline as a shield against torpedoes and shells. Torpedoes may have hit the armor belt and detonated, Dr. McLaren surmised, but may nevertheless have done no damage other than making insignificant dents.
The next month, in July 2001, the British arrived with an expedition of their own, financed by British television and supported by the Ministry of Defense and British veterans groups. Using a tethered robot, the expedition found provocative gashes below the armor belt where the lower hull met the seabed.
The Americans assumed that the Bismarck's rough landing on the mountainside had made these openings - "mechanical damage," as Mr. Lange of Woods Hole put it. But Mr. Mearns, the British expedition leader and director of Blue Water Recoveries, an experienced deep-sea salvage company in West Sussex, England, saw them as evidence of enemy fire. "My feeling," he said in an interview, "is that those holes were probably lengthened by the slide, but initiated by torpedoes."
He ridiculed the idea that torpedoes bounced off the armor belt, but acknowledged that he found no signs of torpedo damage there.
In his book, "Hood and Bismarck," published in January, Mr. Mearns and his co-author, Rob White, concluded that scuttling "may have hastened the inevitable, but only by a matter of minutes."

Dr. Eric Grove, a naval expert at the University of Hull in Britain who went on the expedition, strongly agreed and dismissed the scuttling theory. "I don't believe a word of it," he said. "From what I saw, that ship was very heavily holed below the waterline."

Mr. Cameron's expedition in May and June, with a team of American and Canadian experts, made unusually long dives. As with the earlier expedition, he hired the Russian Mir minisubs, run by the P. P. Shirshov Institute of Oceanology, based in Moscow. Each of the twin submersibles can hold three people.
From them, Mr. Cameron's team deployed tiny robots to probe inside the wreck and closely examine its exterior. He said little publicly about his findings until now.
High on the hull, he said, his team found a few shell holes but none below the waterline or big enough to quickly sink the ship. He also found no torpedo damage on the armor belt, echoing previous findings.
Down low, however, the explorers discovered much.
First, Mr. Cameron's study of the wreck's lower reaches and nearby debris fields led his team to a new explanation for the hull gashes previously attributed to torpedo hits or mechanical damage.
The Bismarck, he said, suffered a "hydraulic outburst" when it hit the bottom. Girded by the armor belt, the ship was like a water balloon wrapped in duct tape and then dropped. The belt held, but inner forces caused the sides to bulge out and break in places - especially at the bottom, as the ship slid down the mountain slope.
The surprise, Mr. Cameron said, came when his tiny robots were able to penetrate the gashes into the ship's interior. In two cases, he came upon torpedo holes at the ends of long gashes. But upon sending the tethered robots even deeper into the ship, Mr. Cameron discovered that the torpedo blasts had failed to shatter its armored inner walls. All that was destroyed, he said, was an outer "sacrificial zone" of water and fuel tanks that German engineers had created to absorb torpedo hits and keep interior spaces dry.
"The inner tank walls are untouched by any explosive force," Mr. Cameron said. "So the armor worked."
The German sailors and officers at the heart of the wounded ship, he added, "were protected in the armored citadel." The torpedoes, he said, caused "no significant flooding."
This July and August, after Mr. Cameron's voyage, Dr. McLaren of the Explorers Club and his colleagues again dived down to the Bismarck with the Mir submersibles.
At an Explorers Club program on Oct. 17, Dr. McLaren, who in the 1980's was an instructor at the United States Naval War College, showed videos of his Bismarck dives and told of the new findings.
"Every naval ship is prepared to scuttle," he said afterward in an interview. "If you're going to get boarded, you want to sink it as fast as you can, but leave sufficient time to get the hell out of there."

http://www.fpp.co.uk/History/General/Battleship_Bismarck/scuttled.html

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Personally, I believe the Bismarck was in sinking condition and would have gone down with the scuttling charges. The charges only hastened the sinking.

WW2 dude hit the nail on the head. Charges or no charges, Bismarck was finished. The pounding she sustained at the hands of the Home Fleet on May 27th ensured she would never be seaworthy again.

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It is likely that some or all of the main magazines were flooded to prevent magazine explosions given every main turret suffered penetrating hits. This can be seen in the condition of the barbettes alone on the wreck. Progressive flooding was also a likely culprit with so many holes of varying size over virtually the entire length of the hull. Given the sea state, flooding through these is a virtual certainty.
Whether the crew actually set off scuttling charges (something I find odd anyway as no other navy I know of had such a planned methodology for sinking their ships) makes little difference. The Bismarck was already in sinking condition and would have gone down in any case whether finished by British torpedoes, shell fire, or just progressive flooding.

Cameron's argument that the torpedo defense system held is meaningless. Both California and West Virginia were in the same condition versus Japanese torpedoes at Pearl Harbor. In both cases it was progressive flooding over the armored deck from above that sank the ships as they settled due to torpedo damage. No doubt, that in Bismarck's case the same thing was happening. Water flooding in over the armored deck found penetrations to the main spaces and began to flood them. This progressive flooding is extremely dangerous in a ship. It also sank Titanic.

Here's a good read on the subject

Bismarck's Final Battle - Part 1

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