POSTSCRIPT. Or what the History Channel program did not cover too well.
Diver/historian Paul Lawton originally tried to discover the sunken halves of the USS Eagle. Numerous side scan sonar runs were made off of the Portland Harbor area. Then a few dives were made on the likely/possible wreck sites. The Eagle wreck site was not found. The damage to the wreck halves would have shown whether the explosion was internal or external. It was also hoped that perhaps the back end of the German torpedo would be found, thus providing a real smoking gun. A lot of time, money and logistics were spent on these searches. Try to get about 4-5 divers together and a suitable boat and side scan equipment. T'aint easy.
When one goes on a worthy quest against the US Government it helps to have a congressman strongly on your side to champion your cause. Otherwise people (government employees) will for the most part ignore you. The late Congressman John Joseph Moakley. Provided a lot of support and help by prodding the right people. God bless him, Joe Moakley was getting sicker and his schedule was becoming tighter because of his health. But even then he helped a lot.
The US Archives and the US Navy Archives are huge, beyond belief. You have to know which building, which floor, which row, which shelf and which box to start searching. Senior Archivist Bernard Cavalcanti of the US Navy Historical Center was the one who was actually doing and overseeing the paper search. And there were a lot of dead ends and a very large number of documents that were actually read.
A similiar search was being conducted at the U-boot Archiv in Germany. It cost time and money. They get zillions of requests for information. And their terms are now CIA (cash in advance) only.
The people who did it are long dead. I go along with the theory that the CO for that geographical area was behind the cover-up. The other main factor was that there was a total news blackout about U-boat activities off of our coast during WWII. The latter was done to avoid an embarressment about the US Navy's not being in total control of our coastlines. At the beginning of WWII the US Navy was on the hot seat with Congress and the public for all of the sinkings just off of our coastlines. A lot of oil got washed up on our beaches along with debris and bodies. In frustration the US Navy just made news and info about sinkings and U-boat sightings classified. My opinion is that our having broken the U-boat codes was not a significant reason for this cover-up.
In a little bit of fairness to our Navy, I did a search at the library at the USS Nautilus Museum. While looking for info about US Navy submarines in WWI I made the uncomfortable discovery that there was NO news blackout about U-boat activities. And people were seeing, and news papers were reporting U-boats all over the place. There are a lot of white caps out there. And our own submarines were getting shot at because everyone thought that they were U-boats.
The word chaos comes to mind.