What other "giant vessels in antiquity" do we have proof of?

The largest known to have been all wood construction was the Wyoming....but her length (LOD) excluding booms was only about 100m, as the jib boom and spanker booms (essentially just poles) extended outboard a long way. Even so, she hogged and twisted horribly, let in vast quantities of water through the sprung planks and needed continuous pumping just to stay afloat. Eventually sank with all hands. Just not seaworthy.

The Roman barge probably used to transport an obelisk from Egypt to St Peter's was also only around 100m in length, maximum, and was basically used once for a short voyage and then sunk.

The difference in length between these only marginally seaworthy vessels and the supposed ark is 37m, which is a very significant percentage increase, and wooden vessels 37 m longer than these simply would not float.

The builder of the Dutch "ark" may well have *said* that he built it on a frame of welded steel barges because of "regulations"....but the regulations are there because naval architecture and design parameters would show that a fully wooden construction would not have the longitudinal or lateral strength to be seaworthy....ie, it wouldn't have floated if he'd built the whole thing of wood. the regulations are there for a purpose.