I am building one of those riverboats with a giant wheel thing on the back... when I tested it the paddles barely pushed the boat along, or it may have even been the vtol engines powering the paddles, only moving at 1 mph. Also, the maneuverability has drastically changed when you have a keel on your boat, even the smallest of them. Am I building crappy paddles? To me it doesn't really make sense that a keel (made of structural wings) will seem to keep the boat from going anywhere when it is in the water, yet a paddle also made of structural wings spinning at 100 mph won't push me anywhere.