Brazilian kayak Project

Hello, my name is Gerson, I'm Brazilian and I'm drawing a SOT kayak. Basically I have used the program Delfitship. I came to this model after many hours of effort.
I would like to help with this project. I do not understand much about the coefficients and do not know if the results found indicating whether the project is good. Would you help me interpret this.
Another aid would be about the size of the kayak. (3.80mx 0.70mx 0.26m / 12:46 'x 27.60 "x 10.2")
The biggest use of this is for small boat fishing in the sea, eventually into lakes and rivers. I want a stable kayak, to keep your course with ease, but it is not difficult to maneuver and who goes with good efficiency.
After solving these issues I will make a paper model scale to check any error and only then run it in full size.

I thank the support received.

 

Doesn't look much different than most sit-on-tops.

Should be a decent performer, depending on weight. If you were going for a more traditional kayak, you could use skin-on-frame (S.O.F.). That would save you about 15 to 25 kilos in weight ....

http://www.capefalconkayak.com/The%20modern%20skin%20on%20frame%20kayak.html

You could make an S.O.F. as a sit on top, but you would have to do the design from scratch, I have not seen any plans or articles to help with building that way.

Wayne

 

for fishing you would want a stable platform so you can relax while fishing. I would go with a slight flatter bottom and hard chines. you loose a little paddling efficiency, but I think it would be a good compromise, and kayak hull forms are already pretty efficient paddlers compared to other hull forms.

The lower you can make your center of gravity, the more stable it will be as well. SOT tend to have a high sitting position, and than have to be very wide to be comfortable, and end up very poor performers for paddling. Keep the your seat as low as possible and you will have a better paddling kayak.

good luck.

 

What crew weight and height of center of gravity of the body did you use?

 

Thank El_Guero, but I want to make a kayak fishing and want a stable and reliable boat for fishing offshore

Thanks Petros, put the kayak seat as low as possible so that the center of gravity is low and give more stability to the boat. The final width will be at 74 cm or 30 inches. And I think the height of 12 inches is enough for a kayak with this use.

Gonzo, I'm 1,77 m and 82 kg this information is helpful to your question?

Thank you all for your cooperation.

 

that is a very wide kayak hull, I like mine to be about 21", but I do not fish in it. Even the factory kayaks seldom are wider than 24 to 26 inches unless they are very short. 12 inches is also very deep, that would be okay for the max overall depth near the center, but it need not be more than about 6 to 8 inches deep at the ends.

what you have is more like a canoe, a large stable cargo hauler, kayaks are generally much smaller and more sleek. When they are that tall they tend to get blown around in high winds. Many of the commercial factory kayaks suffer this problem, they are too large and tend to get blown around a lot, and not easy to paddle when they are too wide. I think a good performing kayak need not have much more than about 4" to 5" of freeboard, the sleek native style kayaks are almost awash when fully loaded. this makes a better performing kayak, particularly in rought seas and high winds.

Your goals might be different of course, but you might consider building a quick skin-on-frame version of your lines, you can even use plastic sheet and duck tape for the skin. It does not have to be pretty, just throw it together with rough 1x2 lumber and plywood frames, lash it together and cover it with sheet plastic and go try it out. put sand bags in it to simulate your estimated build weight. I think you will find it does not have to be so large to make a comfortable kayak, with your cg low you do not need a lot of volume, nor a lot of width. A simple low cost test build to try it now is better than building a mould, using a lot of fiberglass and foam, and than find out it is slow and clumbsy, heavy and not very pleasent to use unless you are just sitting still on calm waters.

good luck.

 

Use an ama (second hull) to keep your balance.

I would also recommend a decked canoe over a kayak for fishing. Kayaks tend to be more about staying very close to the water, wet. And canoes about staying dry.



http://sailingcanoes.dragonflycanoe.com/16_30/

http://www.kayakfishingstuff.com/drupal/content/diy-kayak-outriggers