Well done you put a lot of effort into that including risking your investment with some close proximity flying. Were you tempted to go out and view the container ship?
Tips for improvement would be to work more movement into your shots. A mix of speeds from very slow to as fast as you can fly it. Video is all about motion. Static hovers often don't work that well. Better to have forward motion even if its at a slow pace. Get close to objects but not necessarily that close !
I loved the shot of the people posing for the photograph. People are always more interesting than things, include them as cutaways whenever you can.
Flying through tight spaces can be very impactive however it needs to be smooth and fast for maximum effect. Strive for smooth and then speed it up during the edit.
Last but not least only use your absolute best material. Starting with your strongest shots to pull the viewer in. A youtube audience rarely watches past 20 seconds of a video unless it has some connection to them. Keeping it short makes it easier to edit, upload and watch.
Good effort and keep the videos coming
Shrimpy