Hmmm, no! The German U-boats went up and down the Atlantic Coast not the Pacific. German U-boat commander Admiral Karl Dönitz implemented Operation Paukenschlag (“Drumbeat”). Drumbeat was a U-boat attack on the US east coast, but the U-boats never came within 200 miles of the coast. Nevertheless, some US ships did get sunk by Nazi U-boats off the east coast. However, British intel had a fix on the U-boats and informed the US Navy, but the U.S. Chief of Naval Operations disregarded the Brit's intel.
I would love to see the "primary documents" about torpedoes being found on the beaches of California. Even if torpedoes were found it does not mean the Japanese were close to the west coast. We are talkin 60 some odd years since WWII ended, those torpedoes could have been swept to the west coast in numerous different ways over the years. There is no real "proof" how those torpedoes ended up on the beaches of California, even if it is true, there would be no way to explain that phenomenon.
Now, I know there is proof about "Japanese Balloon Bombs," that were launched and aimed at America. I believe 9,000 were launched and 300 landed in mainland USA. Consequently, I "think" six civilians died from the bombs exploding.