: 'A Friend' (hehe) is looking at building a stripper, and likes the
: Outer Island from Uncle Jay. He's 6'4", weighs around 200#,
: wears size 14 shoes. Apparently Uncle Jay has indicated those
: size flippers won't fit in the Standard OI - but despite an
: exchange of emails, my 'friend' says he hasn't received
: clarification. So being such a great guy, I told him I'd ask
: here.

: Presumably the correct approach is to simply enhance the superior
: aspect of the forms going forward, to allow some wiggle room.
: Are there any particular guidelines, or is it trial by error?

I think it depends on how much extra work 'your friend' wants to put into the project, and how good 'he' wants the boat to look.
Once you have the plans in hand, you would need to mock up a (several, probably) 'foot box' for testing, using the appropriate station for the hull section.
From there, the 'correct' way to proceed IMO would be to re-loft the deck, which is a bit of work, especially if you didn't like geometry & drafting class in school.

I've got an Outer Island; it's a nice-looking boat. Faced with the same problem as 'your friend', I'd probably look for a different boat to build, unless there was something about the handling quality of the OI that I couldn't find elsewhere.

Your friend could always copy a commercial boat that he liked, if he could borrow or rent one for long enough to grab the lines.