There was some good advice from Paul. However I want to clear the basics of resistance:

Very roughly two things slows the kayak down:

In slow speeds (compared to hull's waterline) frictional resistance is only thing that matters. Skin friction comes from surface area and thus as little wet surface the better. As kayak width is increased and lentgh decreased, the surface area drops.

Thus shorter and wider kayak has lowest resistance in slow speeds.

The bad thing for this is wave making resistance. Short kayak will start to create waves in lower speeds and because it's wider the wave making will increase resistance more.

Longer kayak will have a bit more skin friction, but the wave making starts in higher speeds and as a narrower beam, the wave making will not be so much as with shorter and wider kayak.

So, that's the basics.

In reality the paddling is more efficient in narrower hull. In wider kayak paddle will move more far away from kayak's center and part of the store power is lost. Usually you can get enough floatation to 13 ft hull even it's narrow, just make it higher. I actually just designed a pool play kayak that was 10ft 8inch long and 18"7/8 wide. It was made for 200 pound displacement.

Another thing is that the skin friction difference between 14ft or 17ft kayak is quite small. Especially if the shorter kayak is made narrow. And if you paddle anything faster than really slow pace, the wave making starts to slow you down.

So in general I would turn the question: What is the advantage of short kayak? Storage, yes. But for water 17 ft would generally be better.

The original question was to make a kayak for rolling too - then you would like low back deck and relatively low volume. One example is Maligiaq's (Greenland master) rolling kayak (KOG #92). If you can use Freeship, you could take a look. It's downloadable in my webpage.

Toni.

:... A wide boat is
: harder to propel than a narrow one. If the heavier paddler makes a boat
: which is as wide as your Widgeon (24"), but longer--to suit their
: weight-- they have to paddle as hard as you to move 24 inches of water
: around the boat, and then they have to paddle just a little bit harder to
: account for the added friction of the water on the slightly greater wetted
: skin area. But suppose they built their boat to be only 20 inches wide.
: Their boat would be even longer, with again slightly more wetted surface
: area. But the width of water they would have to push aside would be only
: 20 inches, not 24.
....