I wish people didn't use headline superlatives so much. If you compare this ship to the pleasure craft of Caligula which was destroyed in ww2, you have to start qualifying things by open water vs lake-bound. Caligula had two of them, in Roman times. One was 20m wide and 70m long. They were "carnival cruise line" party boats.

It's a big ship. It's an important find. It's not a supership or a supercog, or a beast, or a behemoth.

It's 9m wide, 6m high and 28m long.

Compare it to these: https://www.google.com/search?q=example+of+a+30m+commercial+...

This class of ship was a significant component of middle age trade and presages even larger ships, which in turn increased carrying capacity. Transport on water is bound by displacement to surface area so a small increase in surface area bounds a larger volume, where drag is bounded in surface area so as ships increase in volume the energy cost per unit carried drops significantly and thus the crewing and sail burden. Bigger ships mean cheaper goods.

Carrying 300 tonnes of cargo in 1400 was pretty good.