aka Treasure of the Living Dead, aka Bloodsucking Nazi Zombies, aka Abyss of the Living Dead, aka Le Tresor des Morts Vivants
How bad is it? It's among Jesus Franco's worst (and he's made almost 200 duds).
Should you see it? No.
There are at least three underwater Nazi zombie movies - none of them are good (I may review "Zombie Lake" eventually). Dubbed (from French) actors seek gold in northern Africa, only to find that it's protected by Rommel's soldiers, who are now zombies. It's full of typical Franco direction; zooms abound and static long shots fill time. It's dull. The makeup is poor. There's one decent scene with a flashback to World War II, but I noticed that the soldiers had very modern haircuts for 1940's soldiers.