Ark: 450ft long, 75ft wide, 45ft high. 3 stories tall with a door on the side. Also had a roof over it.
Compare with the ship/boat Edmund Fitzgerald: 729ft long, 75 ft wide, 39ft high. (and absolutely had ballast and a shaped bow)
Noah's ark "probably" looked a lot like the Edmund Fitzgerald with plenty of ballast (anchor/drogue) stones hanging off of it. They were cut as the waters receded and dry land appeared...ark came to rest.

More info from the internet.
Modern replicas — including Ark Encounter (Kentucky) and Johan’s Ark (Netherlands)
Using the commonly applied royal cubit (~20.4–20.6 inches), this yields:
≈510 ft long
≈85 ft wide
≈51 ft high
They don’t look like a barge. They look like a boat.
Hanging off?
I've yet to EVER hear of a ship like that!
Ballast goes in the BOTTOM, to keep the thing from CAPSIZING!