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STABILITY and CAPACITYTo help you interpret the table below Our canoe plans are well tested, but each has its own unique characteristics. It is important before beginning your project to know what kind of canoe you will be paddling on launch day. We offer some science here to help with your decision. A table of stability and capacity values for the various canoes follows this explanation. Hull Type: Symmetrical(Sym) or Asymmetrical (Asym) Traditional hull shapes are most often symmetrical, that is, the front half is the same shape as the back. (We would always hope that canoes and kayaks are symmetrical side to side!) This shape permits the boat to be paddled in either direction, often in reverse when soloing the canoe. An asymmetrical hull shape in a modern canoe or kayak has a finer front end and a slightly larger aft end. This increases the overall speed of the boat or, if you are not a speed demon, makes the canoe easier to paddle. Planking the boat in either case is not a problem. Although the modern canoes are more efficient, we would suggest that an even more important decision for you is which canoe style you like the look of. Our modern canoes (Freedom 15, 17 and 17/9) all have bows without recurve: they don't curve back toward the middle of the canoe at the top. Some people love that look while others prefer the traditional look.
Stability Factor We wanted to give our customers a reference for the stability of our boats. Our designer Steve Killing came up with the stability factor: the technical description is at the bottom of this page, but the real value is in comparing with other boats. Numbers range from about 50 to 115 - the larger the value, the greater the sideways stability. Many novice canoeists find boats below 95 to be just a bit skitterish, around 100 to be average and over 105 to be very stable. Your experience level will determine the stability you need. Optimum Capacity These capacities are the total weight of canoe plus contents that we know works well in the boat. The canoes can be loaded more heavily, but their performance will begin to suffer. For example, the Freedom 17 is listed at 150-510 lbs. The 150 would be a small person in a 50 lb canoe on a solo day paddle. The boat also performs well with two adults (340lbs), plus packs (120lbs), plus canoe (50lbs). We know you can do the math. 
400 lbs (except singles at 250 lbs). The values are the metacentric height at 15 degrees of heel with: 12.24 taken as 100 percent for canoes We were striving for an easy way for paddlers to compare the stability of various canoes and kayaks before they start building, or before they buy a canoe. I now use this for all canoes and kayaks that I design, including BlueWater and Bear Mountain designs. No single number will tell the whole story, but l think this number has guided many people to the correct canoe and avoided big surprises on launch day. The calculation is done on the computer defined shape. I load the canoe to 400 lbs for a tandem and 250 lbs for a single and then heel it to 15 degrees. The software maintains the correct displacement as the boat heels. Once in this attitude the stability is related to the distance from the center of gravity (which I set at the waterline for all canoes as a base point) and the metacenter. The metacenter is the point (usually about 12" above the waterline) where the vertical line through the center of buoyancy intersects the centerline. The higher it is the greater the stability. The determination of the metacenter is not easy without a computer program and to do a physical test on an existing boat in the water is very difficult, so it is easiest to have the designer determine these numbers. Once the metacenter at 15 degrees has been determined, the stability factor is simply the metacentric height in inches divided by 12.24 (for kayaks use 7.50) times 100. A Stability factor of 111 is comfortable for all novices - the Freedom 17'9 A Stability of 100 is comfortable for most paddlers - the Bob Special is at 100 Some novices will feel a boat at 98 to be initially tender, but after a few paddles will be quite comfortable - the Freedom 17 The Huron Cruiser at 92 is not comfortable for most novices Hiawatha at 88 is a challenging boat for some canoeists to paddle. The marathon at 49 is well beyond my skill level. I hope this has been helpful. There is a discussion of stability (although not specifically the new stability factor) in the design chapter of 'KayaCraft' by Ted Moores (available from Bear Mountain) , and in my own book 'Yacht Design Explained' available from www.amazon.com Regards, Steve Killing |
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