2. How Does Indy Survive The U-Boat Trip?
Raiders Of The Lost Ark There is a point in Raiders of the Lost Ark in which Indiana Jones evades capture on a German U-Boat over the course of a lengthy journey but unfortunately due to, a quite abrupt, scene change, we only see Indy at the end of the journey and are never shown quite how he survives without being spotted and captured by the crew. Whilst many believe that it is nigh on impossible for Indy to have survived this journey, there is actually a highly plausible answer. German U-Boats actually used engines that were powered by Diesel, which not only needed air to run safely without fear of exhaust gas poisoning, but could also move significantly faster on the surface of the water than when they were submerged. Thus, the U-Boat would have had no reason to drop below the surface of the water, allowing Indy to stay on top of the U-Boat and easily avoid detection without worrying about the risk of drowning or being left in the middle of the ocean.
The fact that the film is set in 1936 adds further weight to this answer, as the Second World War had not yet started, the U-Boat would not have come across enemy vessels and so would have had no need to shield their presence by submerging their vessel. Despite this, in the Graphic Novelisation of the film, Indy ties himself to the U-Boat's periscope with his whip and is eventually near death upon its arrival at its destination. However, when we see Indy in the film, he is alive and well upon the ship's arrival and so different events have clearly taken place, most likely the U-Boat having travelled much quicker atop the water's surface.