I have had a number of questions about a take-apart kayak, and a few have been built by f x Dan Caouette, Rune Eurenius and Daniel Norlén.
The first attempts were just a kayak cut in two, bolts, nuts and a rubber seal added and hope for the best. But soon bulkheads were added to get rid of the leakage problem. Then Rune Eurenius got the idea of attaching the bolts from the outside, to be handled without reaching deep into the kayak and to get rid of the protruding bolts that made handling risky. Together with what may have been my contribution – the shaped bulkheads that fix the parts solidly and relieves the bolts of parts of the load (shear loads)– it may look like this:
The partition is best done behind the cockpit and in front of the foot support, resulting in three similarly sized parts.
A take-apart kayak is primarily built when the workshop/garage is not long enough or to be able to fit the kayaks into the car instead of on the roof racks. But such a kayak will become slightly heavier and may lose a little of the structural strength of the original one-piece version.
Here is another solution, a bit more elaborate but very clever, for a laminated kayak: https://www.youtube.com/watch?v=YgXmsAyeCkI