U-133's mission to destroy the Hoover Dam According to an article from 1996 U-133's last mission was to travel up the Colorado River from Baja, California and destroy the Hoover Dam. The article is from the USS Shaw's newsletter. The article states that U-133, piloted by Captain Peter Pfau along with 54 sailors made it to as far as Laughlin, Nevada before sandbars made them abort their mission and scuttle the sub. This is only a cute story, U-133 would never have made it that far (see map showing its approximate path from St. Nazaire, a suitable base, to the target) as its fuel supply would never have allowed this (not even close, the type VIIC could make it to the US east coast by filling up part of its water tanks with fuel but even then it was stretching it). There was also no U-boat commander named Pfau. Had such an unusual and daring raid been attempted during the war, people would talk and we would know about it by now. Follow up: A reader pointed out that "... would also have been impossible for the fact that they would have had to somehow bypass the Parker and Imperial Dams (both of which opened in 1938), would have to traverse the entire length of the Colorado River without being detected (I assume that they would have to be surfaced for the duration of the journey to aid in navigation), and would arrive in the Gulf of California only to discover that the Colorado River is not as traversable as one might think." From U-boat.net's myths and stories section None of it is relevant since U-133 was lost off of Greece in 1942.
This one has been floating around the internet for years -- and if you read the forums, there's a lot of people who believe it! There's a 'picture' of the 'wreck' of the U-boat downstream from Hoover Dam too.
By the time it gets to Mexico is there any water left in the river? (I realize that's a bit of an exageration but ....)
Bugsy Siegel was running Vegas then, so the U-boat crew would have turned up in shallow graves in the desert.