I believe this is a WWII US Navy Sea Bag. No markings that I can find, I see what could be the remains of markings but they are so faint I can't tell anything about them, they could very easily be dirt. What's odd is there are roped sewn into the base on the inside. I wonder what they were used for. Other than the dirt, it looks unused which might explain the lack of markings. For $2, I wasn't going to leave it.