[Someone]

That takes balls:

"The second largest cruise ship in the world, Oasis of the Seas, used this effect as a contributing factor to pass under the Great Belt bridge, Denmark, 1 November 2009, on her voyage from the shipyard in Turku, Finland to Florida, USA.[5] Without the presence of the squat effect, the ship wouldn't have been able to clear the bridge safely - the margin would have been very slight. However, travelling at 20 knots (37 km/h) in the shallow channel, Oasis experienced a 30 cm squat, allowing sufficient room to clear the bridge safely."

So, you are captaining this brand new billion dollar cruise ship, and the deck of the bridge is too low to pass under it. Now, order your crew to speed up as much as they can, and trust physics to do its thing.

[HeyLaughingBoy]

Yes, but the basic technique is (at least) decades old. To transit some of the tighter bends of the Panama canal, ships used the hydraulic effects between the ship and the bank to either pull closer to one side, or as a cushion to push the ship over so it could turn in a smaller radius.

I've never heard of squat being used to make it under a bridge, though. We were just taught that if you were heavily loaded and close to the channel bottom, increasing speed could be a bad idea.

[mattwg]

Yikes, gotta be confident about that one. Apparently the Oasis of the Seas is also able to retract it's chimneys (I'm sure that's not the correct word) to get a bit of extra clearance.

Video of this ship, and it's sister ship Allure of the Seas, going under the Great Belt Bridge:

https://www.youtube.com/watch?v=9Opr17Zw11E

[jug6ernaut]

In the old days of steamers they were smoke stacks/chimneys. These days the are more just for aesthetics afaik. Those they do put some instrumentation on them im sure. Such as GPS/radar/antennas.