Seaworthiness of 20' SeaCraft...

[EarToTheWater]

Hello everyone! First, I want to say thanks to everyone who contributes to this amazing resource! Second, I want to gain an understanding of the seaworthiness of a 20' SeaCraft. For the sake of narrowing the breadth of the discussion we'll eliminate Captain's ability as a factor and focus on the ability of the hull. At some point we can all agree that no matter the ability of the Captain the boat shouldn't be offshore. What is the point at which a perfectly functioning 20' SeaCraft cannot safely be run offshore?

Parameters

20' Seacraft CC with 400lb outboard on a bracket
Assume all the requisite safety gear epirb, lifejackets, etc
Assume all the requisite hardware seacocks, lights, etc

Thanks!