A T-class submarine attack before Denmark Strait

What if a British T-class submarine fired ten torpedoes at Bismarck before Denmark Strait?

A slowdown could be worse than an immediate sinking, because it would expose Bismarck to a much stronger and better coordinated British interception.

A British T-class submarine could put roughly ten torpedoes into the water before Bismarck reaches the Denmark Strait action. A complete miss still leaves the historical operation broadly intact, but even one damaging hit creates a much worse German problem. A slowed battleship allows Hood, Prince of Wales, King George V, and other British units to converge on a reported position. Prinz Eugen might have to remain nearby or attempt a tow instead of separating cleanly. The speakers expect the later scuttling-versus-sinking argument to survive, but the operational result is likely an earlier concentration and destruction of Bismarck.