The ark was not a ship- it was unpowered and was therfore a barge.
The one that does it for me is IKB's Great Britain- first propellor driven ship, fastest across the atlantic, arrived in US with 200tons of coal still in her hold on her first trip, she opened up transatlantic travel- something that today we cannot live without, and most importantly she represents entirely the period in our history where great men could come up with ideas and see them through with sheer tenacity and intelligence, and they worked!
Greg