I can see situations in which it would be useful to 3D print a kayak. Like maybe you want some custom mounts for some specific equipment, or maybe your Mom won't let you order one. But this thing cost WAY more to make than just buying a kayak would. Completely ignoring his custom 3D printer, 26kg of ABS = over $1000 alone. Then when you think that is just the hull with no seat, paddle, ties, etc. I've been in a shitty $400 kayak and a really nice $1200 kayak, and this is a shitty $1200 kayak.
Okay, that aside, I think this is a really cool project, and the final result was very high quality.