When it came time to build the Verazzano Narrows Bridge, legendary oceanliners such as Cunard's original Queen Mary had to be factored into the equation.
"Engineers had to consider what was the highest point the tallest ship would be in order to have the ship high enough above, the water level, mean water level for the ship to pass under and the Queen Mary I think was the highest ship of the time," said historian Ted Scull.
When the new Queen Mary 2 was launched in 2004, as the largest liner afloat, the ship was built for the bridge, rather than the other way around.
"Many people had said to me what would have happened if my calculation would have been wrong, and I always say it would only have been a problem the first time," said designer Stephen Payne.
It is just this tight squeeze that thrills passengers who take part in what has become an on board tradition.
"It is the beginning of our approach into NY Harbor and everyone wants to come up to see it and everyone wants to come up on deck and looking up saying, 'she's not going to fit' but she does, she goes underneath," said Queen Mary 2 Captain Chris Wells.
Any secret to keep a ship this size on course?
"The bridge is actually marked underneath by two special green lights right on the center line which is the highest part of the arch. and we aim for those two green lights and we always go under the middle."
So that's how you go straight, through the narrows.