Sinbad, the Coast Guard Dog
Sinbad was a mixed breed puppy who was adopted by the crew of the Coast Guard cutter Campbell in 1938. He eventually enlisted, meaning he had the proper paperwork to qualify as a Coast Guard sailor, and even had his own uniform. He served for eleven years on the same ship. After a battle with the Nazi submarine U-606, the Campbell was badly damaged and most of the crew debarked. Of course, a good dog never debarks, so Sinbad stayed on with the most essential crew members as the ship was towed to port. Sinbad lived to enjoy retirement and quite a bit of publicity about his service.