Das Boot (] , German meaning "The Boat") is a 1981 German war film written and directed by Wolfgang Petersen, produced by Günter Rohrbach, and starring Jürgen Prochnow, Herbert Grönemeyer, and Klaus Wennemann.
 It has been exhibited both as a theatrical release and as a TV miniseries (1985), in several different home video versions of various running times, and in a longer director's cut version supervised by Petersen in 1997.
Unrestricted submarine warfare is a type of naval warfare in which submarines sink vessels such as freighters and tankers without warning, as opposed to attacks per prize rules (also known as "cruiser rules").
 Prize rules call for submarines to surface and search merchantmen and place crews in "a place of safety" (for which lifeboats did not qualify, except under particular circumstances) before sinking them, unless the ship showed "persistent refusal to stop ... or active resistance to visit or search".
 The Germans disregarded the law during the First World War following the British introduction of Q-ships with concealed deck guns, and in the most dramatic episode sank "Lusitania" in 1915 in a few minutes because they believed it was carrying war munitions.
 The U.S. demanded it stop, and Germany did so.
 Admiral Henning von Holtzendorff, chief of the Admiralty staff, argued successfully in early 1917 to resume the attacks and thus starve the British.
 The German high command realized the resumption of unrestricted submarine warfare meant war with the United States but calculated that American mobilization would be too slow to stop a German victory on the Western Front.
The Other Side (German: Die andere Seite) is a 1931 German war film directed by Heinz Paul and starring Conrad Veidt, Theodor Loos and Friedrich Ettel.
 It is an adaptation of R.C. Sherriff's 1928 First World War play "Journey's End" which had been turned into a British-American film the previous year.
 Paul's film attempted to be faithful to the play, retaining the British setting rather than switching the story to feature German soldiers and going to great lengths to portray the "Britishness" of the characters.
 The film was positively received on its release.
5 June (German: Der 5.
 Juni) is a 1942 German war film directed by Fritz Kirchhoff and starring Carl Raddatz, Joachim Brennecke and Karl Ludwig Diehl.
 The film depicts the events of 1940 when German forces successfully invaded France.
 It was shot on location in France and Germany.
 Constant changes to the film, often at the request of the German military, led to large cost overruns.
 In November 1942 the film was banned by the Minister of Public Enlightenment and Propaganda Joseph Goebbels for unspecified reasons.
 It has been speculated that Goebbels thought the film was not entertaining enough or wished to avoid offending the Vichy government of France.
SM "UC-29" was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: "Kaiserliche Marine" ) during World War I.
 The U-boat was ordered on 29 August 1915 and was launched on 15 July 1916.
 She was commissioned into the German Imperial Navy on 15 August 1916 as SM "UC-29".
 In an eight-month career, the "UC-29" performed seven combat patrols into the Atlantic Ocean during the German war on Allied trade ("Handelskrieg").
 In these patrols she was very successful, sinking 18 allied ships, totalling 21,903 tons.
 She also damaged 3 ships of 15,859 tons.
 On 7 June 1917 she torpedoed the British Q-ship  off the Irish coast, but was ambushed by her hidden armaments when she approached too close and was sunk with 23 hands.
 "Pargust" was commanded by British submarine hunter Gordon Campbell and had on board Ronald Niel Stuart and William Williams, who were awarded the Victoria Cross for their actions in the engagement.
Legion Condor is a 1939 German war film directed by Karl Ritter and starring Paul Hartmann, Albert Hehn and Fritz Kampers.
 The film portrays the German Condor Legion which fought in the Spanish Civil War.
 Because of the Nazi-Soviet Pact, the film was pulled from distribution in August 1939 to avoid offending the Soviets who had supported the other side in Spain and who were negatively portrayed in the film.
The sinking of the Cunard ocean liner RMS "Lusitania" occurred on Friday, 7 May 1915 during the World War 1, as Germany waged submarine warfare against the United Kingdom which had implemented a naval blockade of Germany.
 The ship was identified and torpedoed by the German U-boat "U-20" and sank in 18 minutes.
 The vessel went down 11 mi off the Old Head of Kinsale, Ireland, killing 1,198 and leaving 761 survivors.
 The sinking turned public opinion in many countries against Germany, contributed to the American entry into World War I and became an iconic symbol in military recruiting campaigns of why the war was being fought.
Sinking of the Lusitania: Terror at Sea (also known as Lusitania: Murder on the Atlantic, in German: Der Untergang der Lusitania: Tragödie eines Luxusliners) is an English-German Docu-drama produced in 2007.
 This 90-minute film is a dramatisation of the sinking of the "RMS Lusitania" on 7 May 1915 by a German U-boat, "U-20" .
 The "Lusitania" scenes were filmed with full-scale sections of the ship off the coast of South Africa while the "U-20" scenes were filmed at Bavaria Studios in Munich using the then-newly refurbished 25-year-old U-boat set, studio model and full-size prop originally built for "Das Boot".
Cruiser Emden (German: Kreuzer Emden) is a 1932 German war film directed by Louis Ralph and starring Ralph, Renée Stobrawa, Hans Schlenck and Werner Fuetterer.
 It is a remake of a 1926 silent film "Our Emden" which had also been directed by Ralph.
 The film depicts the German First World War cruiser SMS "Emden" .
Comrades at Sea (German: Kameraden auf See) is a 1938 German war film directed by Heinz Paul and starring Theodor Loos, Ingeborg Hertel and Julius Brandt.
 The film is set during the Spanish Civil War, which it portrays as a Communist uprising against the lawful government.

Question: Who directed the German war film that had studio props reused in the film "Sinking of the Lusitania: Terror at Sea"?
Answer: Wolfgang Petersen