Thus the Sea Spirit Kayak was launched     

After paddling for a number of years in kayaks that I couldnít easily lay my back onto the rear deck I decided to take the plunge and build a kayak that I could comfortably lay my back onto the rear deck
I didnít have any boat building know-how so I decided to build a kayak from a kit.  The closest kit I could find that had a chance of meeting my criteria was a CLC North Bay.  I bought the kit, and modified it to the best of my ability.  It resulted in a pretty good kayak, but was to heavy as I used too much epoxy.
After that I decided to design my own by radically modifying the North Bay design.  I just scaled the offsets to what I thought would result in the boat I wanted.  I did that and built the boat.  I also got some experience using graphite powder.  The boat turned out to have little initial stability but good secondary stability.  However, I still couldnít get the lay back I wanted.
Trying again with another North Bay, the result  came out a lot closer to what I wanted.  At this point I discovered hat hull design software was available and bought ProBasic from New Wave Systems.  It was the same software that was used to design the North Bay.  Now I could start with a clean sheet of paper and come up with the design I wanted.
Basing the design on a traditional Greenland skin kayak seemed like a good idea, but I didnít like the idea of the toes of my feet sticking up into the canvas deck.   I wanted more room for my feet.  The depth of a Greenland kayak made for rolling I learned was the width of oneís fist and a kayak made for racing was the width of oneís fist with an extended thumb.  This meant for me the depth would be 3-1/2 in. for rolling and 5-1/4 in. for racing.  I wasnít going to do any racing, but wanted to be able to roll a lot better than I could. (It took me a few years to learn how to roll, and my roll wasnít all that reliable)
I couldnít bring myself to build a kayak with a 3-1/2 in depth, but 5-1/4 in was in the realm of possibility.  I figured that a plywood hull with anything less then 5 inches would break apart during the building process.  I knew I needed at least an inch for the coaming height off the deck.  That would bring the rear deck to 5 inches.  So I opted for the 5-1/4 in just in case I would race.
Now, what about room for my feet?  No way was it going to be 5-1/4 in.  I surveyed a few kayaks, some that I owned and others I didnít, and came to the conclusion that 12 inches in depth from coaming front to the keel would be very comfortable.  I proceeded with these dimensions in mind, and built a cardboard mockup of a hull design I created with ProBasic.  The hull itself looked OK, but I was suspect of the 12 in front coaming depth.
The hull I built out of 4mm Okoume hull had a 5-1/4 in depth at the rear bulkhead.  I built a cardboard mockup of a coaming section with a 12 in depth at its front and taped it to the hull.  Sitting in the hull, I felt rather comfortable with plenty of room for my feet, but it just looked horrible to me.  I then proceeded to lower the coaming, making compromises between appearances and comfort, and settled on 10-5/8 in.
VCP hatches are my favorite type, and find they are simpler to recess in a flat area. This meant the deck would  have to slope from round to flat just before the area where the hatch would be. I chose the slope angle based on my toes clearing the underside of the deck by 1/4 in.
I also wanted the bow and stern tips to be blunt and have a curved look to them, such as a traditional skin boat would have.  This meant that the sides of the hull would have a gentle curve bending away from the natural curve of the hull.  Adding contoured spacers at both at the deck line and the overhang at the bow and stern I decided could best do it.