I go through a protocol that involves cruising along on the surface (with a little TC) and then diving every couple of hours to take sonar readings for a few minutes. Then it's up to periscope depth, a quick check for aircraft or enemy ships, and then surface and cruise. It keeps me occupied and, every now and again, we come across a juicy target.
While cruising in safe waters, such as the Kiel Canal, I switch on the radio, or phonograph, and listen to some vintage music and news broadcasts. Nice.
