Thanks. That's my thought process too.
BTW, the underside is 10 gage and top is 11 gage steel.
I still suspect that Brewer's design displacement is optimistic, and actual displacement is probably higher.
And in any case, the builder, with Brewer's approval, deviated from the plans by stretching out LWL for a finer entry, added a substantial one-foot bow sprit, and added a deeper keel, all of which is going to add some steel. So I've got both an optimistic designer displacement to contend with, and weight added on account of deviations from the plans.
I'm guessing actual displacement is probably closer to 18,000 lbs. The balance of measured weight is "stuff" on or in the fully equipt and loaded boat.
I've been trying to figure my boats SA/D relative to how other boats SA/D are figured. So far it it's been an apples to oranges kind of thing. But I think I'm getting it narrowed down.
Of course, it doesn't help that the sail plan is different from the plans too, but I got the SA kind of figured out.