Iron Barnacle Progress

For our final Engineering project, we need to construct a boat that will travel 500 feet down the back of our local creek. I have picked a catamaran/pontoon design. The stern area will feature an angled bottom so the water pushes the boat forwards while at the same time offering stability. I made the pontoon noses as thin as possible to allow fluid water movement, but also to keep the boat going straight. All the weight (if I have to add any) will be stored in a secret compartment within the superstructure. I need to add those stern parts tomorrow, and also the final touches to the keel/fins. I worry this boat may clip the rocks in the stream, however. I need to take a trip and study the river before making any final decisions.