Everyone jumps to the conclusion that since this is a World War I picture the enemy the Americans are fighting must be the Germans. However, since the setting of this movie is the Adriatic, the enemy is actually the Austrians (or to be more exact, the Austro-Hungarians). You can just make out the Austrian Naval Flag on the sterns of the enemy ships in several scenes. The climactic battle is an attack on Durazzo (Durres in Albania) which was a major Austro-Hungarian naval base in WWI and the site of two battles in that war, the second battle in 1918 being a major allied victory which undoubtedly served as the historical basis for the battle shown in this movie. Some may be thrown by the "Iron Cross" type markings on the attacking enemy airplanes, but these were in fact the markings used on WWI Austrian aircraft.
I only gave this movie a 5 because frankly I found the part about the romance between Montgomery and Evans poorly written and overly melodramatic. But I was impressed by Walter Huston's performance, which gave dimension to a character who could have been played as only a martinet.
The real standout of this film were the battle scenes. As some have noted, actual WW I footage was woven into some scene, though others were obviously done using models. The battle scenes were uniformly quite grim and therefore realistic, equal or better to similar scenes in WW II films. Others have mentioned the memorable scene with Sterling Holloway (I was afraid it would give me nightmares) but I also was struck by the cries for help from sailors diving into the sea in a panic from torpedoed and sinking ships.
In this movie, the combatants were neither extraordinary heroes nor snide villains, but just ordinary men doing their jobs in a nasty, nasty business.
Review of Hell Below
