I could be wrong, but I think that max weight rating may be based on
it's bouancy when swamped. We also have a 12' and our experience is
pretty much identical to Jere Lull and Bobsprit's (except we use our
little 2.5hp outboard more than we row - just lazy, I guess).

At the Nowalk Boat show last year I was told that those were the "safe"
operating weights. That was from the Portaboat rep. While you can always
overload a dinghy, I like the fact that my 2 foot shorter Quicksilver still has
a "safe" limit of 1150 lbs. I like the Portaboat, looks aside, but like ANY
tender it has it's weaknesses.

RB