No. The main deck would be at the “top edge” of the hull and run from Stem to stern. And on many ship would be the top deck that you could see from outside the the ship. There would be no point in having the lower decks exposed, that is except possably a cruze ship might be open to provide passenger walkways or balconies.
I’m no expert on boats or ships (whatever the difference may be), but the volume of the craft below the waterline is what will count in total tonnage that can be carried. So it wouldn’t surprise me if that’s what the dimensions in the link referred to. You could put a platform the size of a football field on top of the deck and it wouldn’t change the significant carrying capacity of the vessel.
Also draft is an extremely important dimension for a boat. It is the key dimension for what ports a boat can call at. So I am sure the dimensions are length width and draft. Tramp steamers ideally would have shallow draft so they can call at a large number of ports as the demands of trade come and go.
Not really true. I suspect you are making a point about displacement, but because much cargo is less dense than water the tonnage of a ship is a measurement of volume and much of that volume is above the waterline.
You and I both participate in threads on ships quite a lot and it stands out to me how often you use terminology quite different to that which I am used to. I suspect that the Jones Act has meant that American seafarers have developed or retained their own nomenclature while the balance of world merchant shipping has diverged.
I see that tonnage does not mean what I thought it did. But my point remains the same. The total weight of a ship including cargo is limited by its displacement. And in the case of giant monkeys, they are probably the same approximate density as water.
This is all very fascinating and you guys have led me to some interesting resources.
I’m still trying to find the deck plans of the Venture. Had no luck with that online.