The connection between Shipping and Physics

Last Updated: August 3, 2026

Inspired by Georgia, (one of the readers of this blog), in this article I take you back to the REAL basics – the connection between Shipping and Physics..

I wrote earlier that the big floating thing that carries our cargo from point A to B is referred to, as a SHIP or a VESSEL and outlined the difference between these two..

Like me, I am sure many of you would have (and if you are in the shipping industry you SHOULD have) thought about how this massive thing that can carry 18,000 + TEUs float so solidly in the water whereas if you throw a small pebble in the water, it sinks so easily..

Well, I have 3 words for you – DISPLACEMENT, BUOYANCY, DENSITY..

The man credited with discovering the physical law of buoyancy is Archimedes..

Science Niblets explains below how the principle named after him (Archimedes Principle) works :

“The reason that a ship floats is that it displaces a lot of water. The displaced water wants to return to it’s original location, where the ship is now, and this pushes the ship upwards. The force which pushes the ship up is called the buoyancy force.

It appears due to the Archimedes’ principle: “Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.”

That means that when an object displaces one liter of water, the object gets pushed up with the buoyancy force equal to the weight of one liter of water. The more water that is displaced, the stronger the buoyancy force is which pushes the object up.”

I also found a very interesting infographic from Bolsover Cruise Club which explains quite visually how these 3 words interact to keep a ship afloat..

Thanks to Georgia for forwarding below links to me..

http://www.science-niblets.org/physics/why-can-heavy-steel-ships-float.html
http://www.bolsovercruiseclub.com/cruise-infographics/why-do-ships-float/#.VW2wWGakd4q
http://hyperphysics.phy-astr.gsu.edu/hbase/pbuoy.html

In their article “Why steel giants are able to float”, Hapag Lloyd provides some new angles to the discussion like the difference in density between salt water and fresh water.. You can read it here..

If you have any educational infographics, videos, images etc that you would like to post, please let me know..

Bita January 27, 2021 At 5:44 PM

Oh man, we are learning about this on high school, and this one single visual has taught me so much more in addition to the professor’s long lectures !!!

Thanks to the author!!!!!!

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Sameerah July 31, 2018 At 2:23 PM

This information was certainly helpful, cant believe am just seeing this

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Erin Hollie August 27, 2015 At 8:59 AM

The connection between shipping and physics is relational. It is logical that there is a physics involved in the displacement of water through the ship. Physics is an important subject in the shipping industry. The people of merchant navy study nautical science in which physics form an important subject. The mariners in their career phase study nautical science as a part of their course.

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Rafael M August 13, 2015 At 5:54 PM

Hello,
Really good Info…

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- Hariesh Manaadiar August 13, 2015 At 7:34 PM
  
  Thank you Rafael..
Pande July 24, 2015 At 4:15 AM

Good… good.. good

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richard July 2, 2015 At 5:18 AM

thanks for reminding me of knowledge from high school! lol

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- Hariesh Manaadiar July 2, 2015 At 11:55 AM
  
  Hi Richard, as I said, its back to basics :), but always good to keep refreshing ourselves.. I was certainly refreshed..
L.R.Stewart July 1, 2015 At 5:09 PM

The presentation relayed is quite useful and friendly to both eye and understanding basics ; however some terms may have to be reviewed or replaced such as :

i) the amount of water that it moves -….. should specify : when static or idle ¡ as when a vessel ” moves ” and understanding by this term that it has velocity ( vector magnitude) a following amount of water appears to fill in the original water void ” displaced ” Yes ? ; this compound effect is termed virtual displacement ; and

ii) respectfully suggest that term ” sink” should be further elaborated on replaced by ” increases its draft “. It will sink once reserve buoyancy has disappeared

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Shankar Pilane July 1, 2015 At 1:50 PM

Really good info. Thanks for sharing Hariesh.

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- Hariesh Manaadiar July 1, 2015 At 1:56 PM
  
  You are most welcome Shankar.. Please do share it with your peers as well.. You can also contribute through comments on all the topics..
jay July 1, 2015 At 11:10 AM

Very useful. Appreciate your kind sharing.

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- Hariesh Manaadiar July 1, 2015 At 11:31 AM
  
  Hi Jay, glad that you found the article useful..
Kishan Barai July 1, 2015 At 7:14 AM

Nice article

– Kishan Barai

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- Hariesh Manaadiar July 1, 2015 At 8:35 AM
  
  Thank you Kishan.. Please do circulate to your peers so they can also benefit..
Sriram July 1, 2015 At 4:37 AM

Excellent basics. Thanks. It helps a layman to understand the concept…

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- Hariesh Manaadiar July 1, 2015 At 8:35 AM
  
  Hi Sriram, glad you found it useful.. Pls do share it with your peers..