The Battle of Hood and Bismarck - Full WWII Documentary
Just 'discovered' this YouTube video which is a fascinating documentary effort to locate both of these iconic ships in the Atlantic. Plaques honoring the fallen were placed at both sites, but at the time of filming Ted Briggs as the sole survivor of HMS Hood, was on board the search ship and pulled the lever that released the plaque (skip to 52:00 if you want to view this). Interviews with survivors of the Bismarck and other ships in the battle are also included.
Recent efforts to recover the bell of HMS Hood have not been successful. Many feel it should remain with the ship. I'm not aware of any recovery efforts for Bismarck, but they've been going back to the site since 1989.
https://www.youtube.com/watch?v=aPgUkr_yafg