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The way PakCanoes handle is confusing because a couple of parameters come into play that we don't consider in traditional canoes. PakCanoes have more flexible hulls, and flotation has been added in unusual places.
Hull Flexibility
Because of the hull flexibility it is a common perception that folding canoe bottoms "oilcan". Oilcanning occurs in boats without stiffened bottoms and is very common in large Royalex canoes. The most annoying characteristic is that the bottom "flaps" when you paddle little waves without a load in the boat. A folding canoe's bottom does not oilcan because its bottom is well supported by the frame stringers and is very stiff. The folding canoe hull is flexible because its sides are less stiff. In a traditional canoe the sides form structural I-beams and make the hull very stiff (even if its bottom is not).
The differences in stiffness characteristics have significant implications for handling on the water. Smaller waves that cause oilcanning in some hardshell canoes have almost no effect on a folding canoe. But larger waves do. The shape of the folding boat changes with the wave so that the ends don't plow into the wave, and the result is a much drier ride. A folding canoe can cope with weather that would swamp a hardshell one.
Whitewater poses a similar situation - with one additional benefit for the folding boat. I used to be surprised to have paddlers in hard boats exclaim: "You ran through that?!" or words to that effect. The "that" was invariably a hole that they had been careful to avoid. In a folding canoe holes can often be ignored. What can make a hole more of a challenge than a wave is that the water in a hole contains a lot of air. I know from unenjoyable swimming experience that a human body does not float well in aerated water. The same is true for canoes. When a hardshell canoe dips its bow into a hole, the buoyancy in the hole has to lift almost the whole boat. If the buoyancy is not up to the task, you ship a lot of water. In a more flexible boat, the buoyancy only has to lift the bow out of the hole.
So what are the implications of flexibility for hull speed? I have been looking for an answer for many years, and have only found that it is a complicated issue. The result of a comparison between flexible and stiff hulls depends on the prevailing conditions. There may well be some performance penalties for flexible boats in terms of hull speed under certain conditions. Practical experience over the years indicates that hull speed is a function of the size and shape of the hull, and differences in hull speed caused by flexible vs stiff are not obvious.
Flotation
The amount and distribution of flotation in PakCanoes is unlike any other canoe that we are aware of. There is a certain amount of flotation in the foam floor, but the bulk of the flotation is in inflatable tubes along each side between skin and frame where it also acts as a bumper and tensioning device for the skin.
With no water in the canoe the built-in flotation is irrelevant. Once the canoe has several inches of water, flotation becomes very important. Some canoes have flotation tanks built into the ends. This will keep the boat afloat, and depending on the amount of flotation, it will help keep you afloat as well. But flotation placed at the centerline will not contribute to a swamped boat's stability. Flotation placed relatively high along the sides is very effective at stabilizing a swamped boat because the flotation has to be submerged to make the boat capsize. This placement of the flotation also makes the boat float higher when it is brought back from an inverted position, so it will have less water in it as well. We feel that this is an important safety feature. | 
