Parasite drag is due to skin friction with the water. Water is viscous (sticky), and when we move a hull through it, we drag some water along with us. The more hull touching the water, the more water we have to carry along. Consequently, the less the hull surface area for a given displacement, the easier the boat will be to paddle. Suppose we decide that to get the displacement we want, our hull cross section at the max beam point needs to be 192 square inches. Our hull shape below the waterline could therefore be a rectangle measuring 6 by 32 inches, and having a perimeter of 44 inches. We can reduce the perimeter length contacting the water by changing the hull shape to a semicircle; we would need a radius of 11 inches, and the perimeter would be only about 35 inches, giving a reduction of 20 percent. Sounds great, right? Unfortunately, a semicircular hull has no stability whatsoever; it might be great for a torpedo, but if used in a canoe, the paddler will be spending a lot of time upside down. So, the hull shape is going to have to be a compromise between paddling ease and stability. (We will be seeing a number of compromises as we work on our design.) Wave drag occurs because the hull displaces water; as we move forward, the energy we put into the water by moving it creates a wave which originates at the bow of the boat. The faster we try to go, the bigger the wave gets. There is a simple formula for calculating the theoretical maximum speed of a displacement hull: 1.34 times the square root of the waterline length. If our boat will have a 16 foot waterline (could be typical for a seventeen-foot canoe), our max speed will be 1.34 * 16 ** ½, or 1.34 *4, or 5.36 miles per hour. It is actually possible to exceed this speed, but probably not in a human-powered vessel, because it takes increasingly large amounts of power to accomplish it. So, what can we do if we want to go faster? Why, we build a longer boat! A 20 foot waterline gives us six mph; 24 feet gives us 6.6 mph, and so on. What, you say? You can't fit a 25 foot boat in your garage? Neither can I, so I guess I will have to make absolute speed less important in my design than other considerations. Perhaps I should mention hull asymmetry at this point. It is supposed that an asymmetric hull tracks better that a symmetric hull, and asymmetry tends to counteract the inclination of the boat to 'squat' when moving close to its hull speed. I can not honestly say whether either of these are true, but I designed some asymmetry into my boat, and it tracked well, and was fast for its length. YMMV Finally, we have the problem of steering drag. This isn't really drag, but it is a source of increased energy usage that we must address. When a single paddle is used to propel a boat, the force we exert to move the boat forward, because it is applied off the boat's center line, also tends to turn the boat. Assuming we want to go straight, we have to counteract this turning force by using a J-stroke, which essentially pushes the boat back to where we started before we paddled forward. This lateral stroking can use a lot of energy. The effect is most pronounced for a solo paddler, but is also present with two paddlers, even if they are paddling on opposite sides (as they should). (Aside: I prefer, when paddling solo, to use a double-bladed (kayak-style) paddle. This substantially reduces the effort wasted in steering, since strokes are balanced side-to-side.) We can reduce the effect of the off-center power stroke by making our boat longer, and by reducing the amount of rocker (the amount the keel line rises at the bow and stern). Most commercially produced aluminum boats also have a drop keel that extends an inch or so down, creating even more resistance to turning, but a strip-built boat will not have this. If we build a long boat with no rocker, it will be easy to keep in a straight line. We may find that ease of going straight is the same as difficulty in turning. Sad to say, sometimes we actually want the boat to turn.