I am pretty sure he did consult some scantling rules. I think the uniform building code (not sure what year). He might have done better to consult the more recent IBC but too late now.
If you have started the thread recently and only seen the near-completed hull photos I can see where that could look possible.
From earlier construction photos, though, it's an absurd failure for structural strength.
With regard to framing, it's clear that he consulted no scantling rules, did no engineering analysis, didn't do good guesswork, most definitely did not get it right, and MOST defini