I'd think building without plans would be tough...what would you use in place of lofting an already tested, precise design?  I guess if you had the software you could come up with your own design - but it seems like a lot of work and frustration when there are so many well established plans to choose from.

Good luck whichever fork you take.

Chris

I think that it is possible to build a boat without plans and have varying degrees of success.

Since successful designs tend to be refined over several trials and prototypes, it is unrealistic to expect your first design to be perfect or even good.

What you are avoiding by using good plans is the trial and error and experimenting. You know that if you use resonable care in the workmanship and materials you will end up with a boat of know characteristics. 

I am a designer by training and the modeling and refining of prototypes is what gives you a finished product you like. 

If you have lots of time, are willing to build more than one boat to fine tune your design and don't mind less than perfect performance in early models then go for it. It is an exciting process. If you want reasonable performance out of your first boat then start from plans.

Building from plans is not particularly cheaper than building from kit if you factor your time in but it allows you to go through the whole process at the cost of more opportunity for error and generally it takes much longer.

good luck

Christine

I am assuming you mean to build a boat WITH a set of 'plans' instead of purchasing a complete 'KIT'? You need the plans to mark and cut your wood, minimum.

I looked around and priced around to figure the cost of me acquiring my own materials and buying just the plans and unless you have access to materials at a phenominal price from being on the inside of the industry or can get it cheap in bulk for building multiple boats (with purchasing the right to do so)....you just cannot beat the price of a complete kit, and the wood is already cut for you. There are other things (supplies) you still need to buy and you may need to buy extra epoxy but dollar for dollar for what you are getting, in my opinion it is best to buy the kit.

http://shearwaterkayak.blogspot.com/

You might want to take a look at:

www.blueheronkayaks.com

There are various free programs you can use to design your own kayak. One program is written and maintained by the administrator of that site. There is a forum there where people post and offer critique of various designs. You may be able to download and use or modify designs developed, built and tested by others (where they are willing to allow this).

Guillemot kayaks' kayak builders' board is another good source for information regarding how to design your own kayak, and then build from your own plans. 

You'll probably want some sort of plans? Even if you are starting out with just a log and whittling knife! The question really becomes one of source (your own imagination?) and level of detail.

Take a look at yostworks.com too for many freely available plans and instructions regarding the construction of skin-on-frame kayaks. 

On the other hand, there are many tried and true designs, for which detailed, full-size plans can be purchased quite inexpensively. This very site is a good place to look for those:) 

Ogata 

Rather than trying to build a boat without plans, how about building a cardboard model of a boat without plans? That way you can go through many variations relatively quickly with very little cost until you find a design you really like. Then it is just a matter of expanding the cardboard panels up to full size.

I did just what you are asking about. I knew what I wanted and there was no kit or plans available. In his kayak book Chris K said if you can't find a kit or plans for a boat you want, build it anyway. I did.

I started by looking at plans for a Ches 16 then drew my own similar to it. I built a small scale model and then a full sized cardboard boat. The next step was to built the real thing out of scrap plywood I had. I wasn't sure I was even going to finish it but I did. I glassed the hull, added several cross braces (so it wouldn't collapse inward) and paddled it to see where to put the seat and if it was worth finishing. It was and I did.

After paddling it for a while I built another one for my wife. At each step there were changes (improvements I hope) made as I discovered things.

That was almost 3 years ago. We have paddled those boats more than any others we own. They are great. If nothing else it was fun and a learning experience. Go for it!

you might want to go with strip built then you dont have to worry about the complicated cuts needed to make the panels take the shape you want