Every year in October, some friends of my parents have gotten together at a cabin next to a small pond. As a kid it was one of my favorite times of the year, as it meant I got to hang out with my two favorite cousins and one other friend. One year we got the idea to build a simple wooded boat and attach some model rocket engines to it. We built the boat and launched it from the dock. That boat only went about 6 feet, but an annual tradition was born. Over the next few years we built several more boats - most were dismal failures. Eventually, my brother decided to have a go at building a boat and his boats were considerably more successful. We gradually increased the rocket thrust and even added a second rocket stage. Our most successful run made it around half way down the pond before the boat lifted off the water and tumbled out of control. This year I decided to build my first boat in quite some time - this is the story of that boat.
As our boats increased in speed over the years so did the problems we encountered in controlling them. We did find some key design elements that worked well though. First, we found that a flat bottomed boat was much faster than a deep hulled boat as the water drag was reduced in this configuration. We also found that the boat needed to be sufficiently long so that the rockets did not push the front of the boat down under the water. The boat was also found to have stability issues at speed if it had a large, flat, upward sloping front. As such a boat would reach maximum speed, the air flowing under the angled front of the boat would lift the front of the hull, tumbling the boat in a spectacular backflip.
On Youtube I found videos of high-speed outrigger-type RC boats, like that shown above. Impressed by the stability of these boats at speed, and realizing that they fit all of our key design elements, I drew up a simple design for my rocket boat. I printed out paper templates of the side profiles of the front of the hull as well as the outriggers.