The design theory behind our Double Paddle Canoe
(aka Touring Kayaks)
  The sea kayak design is based on the premise that a long, narrow hull is faster than a  wider hull of similar length. This is true if you are moving at speeds approaching the theoretical hull speed of the boat, which is dictated by the length of the boat. Hull speed is a function of the wave length generated by a particular boat, with longer boats generating longer waves which allow greater speed. Naturally, the act of generating a wave by moving a vessel through the water requires an input of energy (from the paddler in this case); and, the mass of the wave generated is governed by the width of the boat (or, more accurately, the size of the midship cross section). Thus, a narrower hull produces a smaller wave, requiring less energy, allowing more energy to be expended in making the boat go forward. Indeed, this  wave making resistance factor  becomes negligible in very narrow hulls, which is why catamarans are so fast without  planing  off.

   However, all of this is only true when a boat approaches theoretical hull speed, which most paddlers never do, and  certainly never on a cruise or outing with a heavy load of gear on board. And, when boats travel well below hull speed, the greatest resistance they must overcome is simple friction, which is a direct function of wetted surface (the total area of a boat submersed in water).  This where the narrow sea kayak begins to lose its advantage.

    The factor which comes into play here is the ratio between displacement  and wetted surface. Displacement in a boat is  measured by calculating the volume of boat below the waterline, times the weight of water. If the total weight of two boats plus their crew and gear are the same, but one boat is narrower than the other, the narrower boat will have more wetted surface. This is because volume increases at an exponential rate, while surface area increases at a mathematical rate, when beam is increased. An example of this would be:

   We take two tubes, both 10 feet long, but one at 1 foot diameter, the other at 2 feet diameter; The smaller tube has a total volume (displacement) of 502.4 pounds, with 31.4 feet of surface area (not counting the ends). To equal this displacement, the larger tube will float 7 inches deep in the water, but with a total wetted surface of only 23.3 square feet (not including ends).  The smaller tube, with 33 more surface area, will at low speeds use significantly more energy to overcome this added penalty of friction drag.

    The bottom line, of course, is actual speed attained under paddle, which for most paddlers is about 2/3rds of hull speed. For this reason, the lower wetted surface of the wider boat will require less energy to move when loaded down for an extended journey.

    The greatest advantage of the double-paddle canoe concept, however, is pure safety. In any writings about sea kayaks and canoes, one will read about such things as bracing with one s paddle, doing eskimo rolls, wet exits, self rescues, bailing your canoe or  kicking  the water out of your canoe. All of this points to one inescapable fact about canoes and sea kayaks;    
These boats are inherently unseaworthy.

     In a sea kayak, it is possible for a good, practiced paddler to go great distances in all conditions, relying on their ability to use their paddling skills to contend with the sea conditions. The further skills of rolling and self-rescue, or assisted rescue, will get one through the occasional capsizes which seem to be highlighted in all the sea kayaking publications. The trouble with all this is; its all great when it works, but sometimes it doesn t, and this can have tragic consequences. The real question is, why would anyone venture beyond calm, sheltered waters in a vessel which is so inherently unseaworthy that it requires constant perfect skill to survive? And, once a capsize occurs, the small cockpits which are, again, great when the boat is upright and under control, become a hazard which can trap or exclude a paddler.

     It is important to note right here that virtually every long range, even trans-oceanic paddling voyage, has taken place in a boat of the double-paddle canoe type; a boat with adequate beam to be inherently seaworthy, capable of remaining upright while the crew rested (or was sick), with a large open cockpit enclosed with a good sprayskirt.

    The traditional canoe suffers from the basic problem of having the crew weight too high (sea kayaks have the same problem, due to the narrow beam). This manifests itself for a fundamental reason explained by physics. If crew weight is too high, the center of gravity of the main weight in the vessel is too high. Stability in a boat is a factor of  center of gravity in relation to center of bouyancy, measured from sidto side. While a boat on calm water, with its crew sitting on center, will be relatively stable, we are talking about venturing out into open water, where the surface is stirred up by wind, powerboats, and tides. In these conditions, the surface is periodically  tipped , and as a boat tips with the waves, the center of gravity of the crew weight moves off center, until it passes the athwartship center of bouyancy, and capsize occurs.

    With our boats, we keep the crew weight low, with enough beam and  deadrise in the cross section, to make these boats stable and seaworthy in their own right, seperate from  the paddlers skill and ongoing physical capabilities. They have adequate freeboard to be capable of withstanding moderate seas without a sprayskirt, and with a sprayskirt  are capable of long  voyages. The seaworthiness of our boats is enhanced by the decking at bow, stern, and on the sides, which allows for a boat with lower freeboard (and thus, windage) than a traditional canoe to still maintain a higher level of seaworthiness.