We've been going back and forth on hatch design for the Powell boats. All of the second expedition boats show flush hatches so there is no reason to believe that they didn't have them on the first boats. Because these boats are hugely overbuilt we are also using extremely stout deck beams, carlin beams. spur beams, center-line blocking and sheer blocking.
Things are really coming together. If you want something explained, just ask.