"The Last U-Boat" is a highly fictionalized tale of the last mission of U-234, a German U-boat, which, in an almost delicious coincidence, was actually carrying U-235 isotopes (and other war matériel) on a secret mission to Japan, as it were, just as the Third Reich was in its death throes. For a war movie buff, the basic premise is interesting and unique enough, with there being Nazis or various sorts, Japanese, British, and Americans all interacting in various potentially sort of plausible ways.
Before I go any further, let me also say that this movie has basically nothing to do with the original, classic "Das Boot" in any way other than that they both involve submarines and that it appears that somewhere down the line some opportunistic or cynical marketers got the "das boot 2" tag line somehow associated with this thing. Don't believe it! Unfortunately, the execution is poor, and this film deserves nowhere near it's current 6.5 IMDb rating. Basically, the "high level" plot is interesting, but the overall dialog appears to be somebody's first attempt at a screenplay, which begs the question of how this thing ever got made. This is partially answered by the obvious cost savings of not having much in the way of plausible sets, effects, or actors. The actors manage to take already incredibly poor dialog - you know, the type that just screams "I am reading exposition!" and make it seem even worse. Look - this review is operating that this film was shot as a low budget but ultimately "professional" and/or commercial endeavor - it is clear that few of the actors had ever been before a camera before.
Sets and effects: fine, i get it. You can't afford to film some (most) sub scenes inside of an actual sub. But, if you're going to want me to believe, for example, that what is obviously the interior of an old railway sleeping car (Japanese officers' stateroom) is inside of a submarine, would it hurt you to have some engine sounds? As I said - the plot at a high level was decent enough and something could have been made of it. And, I can sort of understand that this low budget movie has low budget "actors" and effects. What I don't understand at all, however, is just how the technical dialog of the movie was so badly massacred. After all, the script seems to have started as the pet project of somebody who, you know, takes an interest in Submarines and WW2. Tell me again how a submerged submarine is using it's "RADAR?" Tell me again how a *SURFACED* submarine manages to possibly sink an *ANTI SUBMARINE DESTROYER*? I'm fortunate enough to speak a little Japanese, so I recognize that some of the Japanese actors were OK, even though they were reading Japanese-language lines clearly not written by a Japanese speaking person (but rather, translated into Japanese). Similarly, the "good" Nazi general had moments of not total acting awfulness, as did the captain. the rest of the movie (including certain scenes by the aforementioned general) features some of the worst acting ever put to film, with special compliments to the "Captain of HMS Liverpool" for being perhaps the worst actor of the 20th century.
