Perhaps it would be of some interest to know that, indeed, Uboat crews were allowed to listen allied radio broadcasting at sea - a thing considered plainly treasonous and highly punishable

back at home.
Scrapes with the law of the Uboat crews were often "smoothened" by their commanders pulling strings behind the scene. Reportedly, this practice and protectionism was very common and well known all the way to even the high command, Doenitz including.